UNITED STATES
                         SECURITIES EXCHANGE COMMISSION
                             Washington, D.C. 20549

-------------------------------------------------------------------------------


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                               (Amendment No. )*

                              GRILL CONCEPTS, INC.
                              --------------------
                                (Name of Issuer)


                    Common Stock, $.00004 par value per share
                -------------------------------------------------
                         (Title of Class of Securities)


                                    398502203
                            ------------------------
                                 (CUSIP Number)


                                December 31, 2007
                            ------------------------
             (Date of Event which Requires Filing of this Statement)


Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

                               [ X ]  Rule 13d-1(b)

                               [   ]  Rule 13d-1(c)

                               [   ]  Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).


                          Continued on following pages
                                Page 1 of 11 Pages
                             Exhibit Index: Page 10



                                  SCHEDULE 13G

CUSIP No.: 398502203                                         Page 2 of 11 Pages

...............................................................................
1.    Names of Reporting Persons.

      I.R.S. Identification Nos. of above persons (entities only).


      MAGNETAR FINANCIAL LLC
...............................................................................
2.    Check the Appropriate Box if a Member of a Group

      (a) [ ]
      (b) [ ]
...............................................................................
3.    SEC Use Only
...............................................................................
4.    Citizenship or Place of Organization


      Delaware
...............................................................................
                      5.  Sole Voting Power              None
Number of          ...........................................................
Shares                6.  Shared Voting Power            547,967/1/
Beneficially       ...........................................................
Owned by Each         7.  Sole Dispositive Power         None
Reporting          ...........................................................
Person With           8.  Shared Dispositive Power       547,967/1/
...............................................................................
9.    Aggregate Amount Beneficially Owned by Each Reporting Person


      547,967/1/
...............................................................................
10.   Check if the Aggregate Amount in Row (9) Excludes Certain Shares
      (See Instructions)


      [  ]
...............................................................................
11.   Percent of Class Represented by Amount in Row (9)


      6.24% based on 8,786,405 shares outstanding as of October 30, 2007./1/
...............................................................................
12.   Type of Reporting Person:


      IA; OO

----------------
/1/ In addition,  the  Reporting  Person also owns  certain  warrants to acquire
Shares.  The warrants,  which are  exercisable  immediately at the option of the
holder,  are subject to so-called  "blocker"  provisions  prohibiting the holder
from  exercising  the warrants to the extent that such exercise  would result in
the holder  being deemed the  beneficial  owner of more than 4.90% of the Shares
then issued and outstanding. See Item 4(a) herein.



                                  SCHEDULE 13G

CUSIP No.: 398502203                                         Page 3 of 11 Pages

...............................................................................
1.    Names of Reporting Persons.

      I.R.S. Identification Nos. of above persons (entities only).



      MAGNETAR CAPITAL PARTNERS LP
...............................................................................
2     Check the Appropriate Box if a Member of a Group

      (a) [ ]
      (b) [ ]
...............................................................................
3.
      SEC Use Only
...............................................................................
4.    Citizenship or Place of Organization


      Delaware
...............................................................................
                      5.  Sole Voting Power              None
Number of          ...........................................................
Shares                6.  Shared Voting Power            797,740/1/
Beneficially       ...........................................................
Owned by Each         7.  Sole Dispositive Power         None
Reporting          ...........................................................
Person With           8.  Shared Dispositive Power       797,740/1/
...............................................................................
9.    Aggregate Amount Beneficially Owned by Each Reporting Person


      797,740/1/
...............................................................................
10.   Check if the Aggregate Amount in Row (9) Excludes Certain Shares
      (See Instructions)


      [  ]
...............................................................................
11.   Percent of Class Represented by Amount in Row (9)


      9.08% based on 8,786,405 shares outstanding as of October 30, 2007./1/
...............................................................................
12.   Type of Reporting Person:


      HC; OO


/1/ In addition,  the  Reporting  Person also owns  certain  warrants to acquire
Shares.  The warrants,  which are  exercisable  immediately at the option of the
holder,  are subject to so-called  "blocker"  provisions  prohibiting the holder
from  exercising  the warrants to the extent that such exercise  would result in
the holder  being deemed the  beneficial  owner of more than 4.90% of the Shares
then issued and outstanding. See Item 4(a) herein.





                                  SCHEDULE 13G

CUSIP No.: 398502203                                         Page 4 of 11 Pages

...............................................................................
1.    Names of Reporting Persons.

      I.R.S. Identification Nos. of above persons (entities only).


      SUPERNOVA MANAGEMENT LLC
...............................................................................
2.    Check the Appropriate Box if a Member of a Group

      (a) [ ]
      (b) [ ]
...............................................................................
3.
      SEC Use Only
...............................................................................
4.    Citizenship or Place of Organization


      Delaware
...............................................................................
                      5.  Sole Voting Power              None
Number of          ...........................................................
Shares                6.  Shared Voting Power            797,740/1/
Beneficially       ...........................................................
Owned by Each         7.  Sole Dispositive Power         None
Reporting          ...........................................................
Person With           8.  Shared Dispositive Power       797,740/1/
...............................................................................
9.    Aggregate Amount Beneficially Owned by Each Reporting Person


      797,740/1/
...............................................................................
10.   Check if the Aggregate Amount in Row (9) Excludes Certain Shares
      (See Instructions)


      [  ]
...............................................................................
11.   Percent of Class Represented by Amount in Row (9)

      9.08% based on 8,786,405 shares outstanding as of October 30, 2007./1/
...............................................................................
12.   Type of Reporting Person:


      HC; OO


/1/ In addition,  the  Reporting  Person also owns  certain  warrants to acquire
Shares.  The warrants,  which are  exercisable  immediately at the option of the
holder,  are subject to so-called  "blocker"  provisions  prohibiting the holder
from  exercising  the warrants to the extent that such exercise  would result in
the holder  being deemed the  beneficial  owner of more than 4.90% of the Shares
then issued and outstanding. See Item 4(a) herein.





                                  SCHEDULE 13G

CUSIP No.: 398502203                                         Page 5 of 11 Pages

...............................................................................
1.    Names of Reporting Persons.

      I.R.S. Identification Nos. of above persons (entities only).


      ALEC N. LITOWITZ
...............................................................................
2.    Check the Appropriate Box if a Member of a Group

      (a) [ ]
      (b) [ ]
...............................................................................
3.    SEC Use Only
...............................................................................
4.    Citizenship or Place of Organization


      United States of America
...............................................................................
                      5.  Sole Voting Power              None
Number of          ...........................................................
Shares                6.  Shared Voting Power            797,740/1/
Beneficially       ...........................................................
Owned by Each         7.  Sole Dispositive Power         None
Reporting          ...........................................................
Person With           8.  Shared Dispositive Power       797,740/1/
...............................................................................
9.    Aggregate Amount Beneficially Owned by Each Reporting Person


      797,740/1/
...............................................................................
10.   Check if the Aggregate Amount in Row (9) Excludes Certain Shares
      (See Instructions)


      [  ]
...............................................................................
11.   Percent of Class Represented by Amount in Row (9)


      9.08% based on 8,786,405 shares outstanding as of October 30, 2007./1/
...............................................................................
12.   Type of Reporting Person:


      HC


/1/ In addition,  the  Reporting  Person also owns  certain  warrants to acquire
Shares.  The warrants,  which are  exercisable  immediately at the option of the
holder,  are subject to so-called  "blocker"  provisions  prohibiting the holder
from  exercising  the warrants to the extent that such exercise  would result in
the holder  being deemed the  beneficial  owner of more than 4.90% of the Shares
then issued and outstanding. See Item 4(a) herein.





                                                             Page 6 of 11 Pages

Item 1(a). Name of Issuer:

           Grill Concepts, Inc. (the "Issuer")

Item 1(b). Address of Issuer's Principal Executive Offices:

           11661 San Vincente Blvd., Suite 404, Los Angeles, California 90049.

Item 2(a). Name of Person Filing:

           This  Statement  is  filed  on  behalf  of  each  of the following
persons (collectively, the "Reporting Persons"):

           i)   Magnetar Financial LLC ("Magnetar Financial");

           ii) Magnetar Capital Partners LP ("Magnetar Capital Partners");

           iii) Supernova Management LLC ("Supernova Management"); and

           iv)  Alec N. Litowitz ("Mr. Litowitz").

This  Statement  relates to Shares (as defined  herein) held for the accounts of
Magnetar Capital Master Fund, Ltd, a Cayman Islands exempted company  ("Magnetar
Capital  Master Fund") and Shares held for certain  managed  accounts  ("Managed
Accounts").  Magnetar  Capital  Partners  serves as the sole  member  and parent
holding company of Magnetar Financial and Magnetar Investment Management,  LLC a
Delaware limited liability company ("Magnetar Investment  Management").  Each of
Magnetar Financial and Magnetar Investment  Management are registered investment
advisers under Section 203 of the  Investment  Advisers Act of 1940, as amended.
Magnetar Financial serves as investment adviser to Magnetar Capital Master Fund.
In such capacity,  Magnetar Financial exercises voting and investment power over
the Shares  held for the  account of  Magnetar  Capital  Master  Fund.  Magnetar
Investment  Management serve as investment  adviser to the Managed Accounts.  In
such capacity,  Magnetar Investment  Management  exercises voting and investment
power over the Shares held for the accounts of the Managed  Accounts.  Supernova
Management is the general partner of Magnetar Capital  Partners.  The manager of
Supernova Management is Mr. Litowitz.

Item 2(b). Address of Principal Business Office or, if None, Residence

The address of the  principal  business  office of each of  Magnetar  Financial,
Magnetar  Capital  Partners,  Supernova  Management,  and Mr.  Litowitz  is 1603
Orrington Avenue, 13th Floor, Evanston, Illinois 60201.

Item 2(c). Citizenship

           i) Magnetar Financial is a Delaware limited liability company;

           ii) Magnetar Capital Partners is a Delaware limited partnership;

           iii) Supernova Management is a Delaware limited liability company;
and

           iv) Mr. Litowitz is a citizen of the United States of America.



                                                             Page 7 of 11 Pages

Item 2(d). Title of Class of Securities:

           Common Stock, $.00004 par value per share (the "Shares")

Item 2(e). CUSIP Number:

           398502203

Item 3.    If  This  Statement  is Filed  Pursuant  to   ss.ss.240.13d-1(b)  or
           240.13d-2(b) or (c), Check Whether the Person Filing is a:

           (a)  [  ]   Broker or dealer  registered under  Section  15  of  the
                       Exchange Act.
           (b)  [  ]   Bank as defined in Section 3(a)(6) of the Exchange  Act.
           (c)  [  ]   Insurance company as defined in Section 3(a)(19) of  the
                       Exchange Act.
           (d)  [  ]   Investment  company  registered  under  Section 8 of the
                       Investment Company Act.
           (e)  [X]    An    investment   adviser   in   accordance  with  Rule
                       13d-1(b)(1)(ii)(E);
           (f)  [  ]   An employee benefit plan or endowment fund in accordance
                       with Rule 13d-1(b)(1)(ii)(F).
           (g)  [  ]   A parent holding company or control person in accordance
                       with Rule 13d-1(b)(1)(ii)(G).
           (h)  [  ]   A  savings association as defined in Section 3(b) of the
                       Federal Deposit Insurance Act.
           (i)  [  ]   A church plan that is excluded from the definition of an
                       investment   company   under   Section 3(c)(14)  of  the
                       Investment Company Act.

Item 4.    Ownership:

Item 4(a)  Amount Beneficially Owned:

           (i) As of  December  31,  2007,  each of Magnetar  Capital  Partners,
Supernova  Management and Mr. Litowitz may be deemed to be the beneficial  owner
of: (A) 547,967 Shares held for the account of Magnetar Capital Master Fund; and
(B) 249,773 Shares held for the accounts of the Managed Accounts.

           (ii) As of December 31, 2007,  Magnetar Financial may be deemed to be
the beneficial  owner of 547,967 Shares held for the account of Magnetar Capital
Master Fund.

           In addition,  each of Magnetar Financial,  Magnetar Capital Partners,
Supernova  Management and Mr. Litowitz also own warrants held for the account of
Magnetar Capital Master Fund. There is a contractual provision blocking exercise
of the warrants when the holder  beneficially owns more than 4.90% of the issued
and outstanding Shares.  Since the Reporting Persons currently  beneficially own
9.08% of the Shares,  the warrants are not currently  exercisable  and thus, the
Shares underlying the warrants have not been included in the calculations of the
Reporting Person's beneficial ownership of the Shares.

Item 4(b)  Percent of Class:

           (i) The number of Shares of which each of Magnetar Capital  Partners,
Supernova  Management and Mr. Litowitz may be deemed to be the beneficial  owner
constitutes  approximately  9.08% the total number of Shares  outstanding (based
upon  information  provided by the Issuer in its most  recently-filed  quarterly
report on Form 10-Q, there were approximately 8,786,405 shares outstanding as of
October 30, 2007).



                                                             Page 8 of 11 Pages

           (ii) The number of Shares of which  Magnetar  Financial may be deemed
to be the beneficial owner constitutes  approximately  6.24% of the total number
of Shares outstanding.

Item 4(c)  Number of Shares of which such person has:


Magnetar Financial:
------------------

(i) Sole power to vote or direct the vote:                                  0

(ii) Shared power to vote or direct the vote:                         547,967/1/

(iii) Sole power to dispose or direct the disposition of:                   0

(iv) Shared power to dispose or direct the disposition of:            547,967/1/


Magnetar Capital Partners, Supernova Management, and Mr. Litowitz:
------------------------------------------------------------------

(i) Sole power to vote or direct the vote:                                  0

(ii) Shared power to vote or direct the vote:                         797,740/1/

(iii) Sole power to dispose or direct the disposition of:                   0

(iv) Shared power to dispose or direct the disposition of:            797,740/1/


/1/ In addition,  the  Reporting  Person also owns  certain  warrants to acquire
Shares.  The warrants,  which are  exercisable  immediately at the option of the
holder,  are subject to so-called  "blocker"  provisions  prohibiting the holder
from  exercising  the warrants to the extent that such exercise  would result in
the holder  being deemed the  beneficial  owner of more than 4.90% of the Shares
then issued and outstanding. See Item 4(a) herein.


Item 5.    Ownership of Five Percent or Less of a Class:

           This Item 5 is not applicable.

Item 6.    Ownership of More than Five Percent on Behalf of Another Person:

           This Item 6 is not applicable.

Item 7.    Identification and Classification of the Subsidiary Which Acquired
           the Security Being Reported on By the Parent Holding Company:

           See disclosure in Item 2 hereof.

Item 8.    Identification and Classification of Members of the Group:

           This Item 8 is not applicable.

Item 9.    Notice of Dissolution of Group:

           This Item 9 is not applicable.

Item 10.   Certification:

           By signing below each of the Reporting Persons certifies that, to the
best of their  knowledge and belief,  the securities  referred to above were not
acquired  and are not held for the  purpose of or with the effect of changing or
influencing  the control of the issuer of the  securities  and were not acquired
and are not  held in  connection  with or as a  participant  in any  transaction
having that purpose or effect.



                                                             Page 9 of 11 Pages

                                    SIGNATURE

           After reasonable  inquiry and to the best of my knowledge and belief,
I certify that the information set forth in this statement is true, complete and
correct.

Date: February 13, 2008         MAGNETAR FINANCIAL LLC

                                By: Magnetar Capital Partners LP
                                       As Sole Member


                                By:  /s/ Alec N. Litowitz
                                     -----------------------------
                                Name: Alec N. Litowitz
                                Title:   Manager of Supernova
                                Management LLC, as General Partner
                                of Magnetar Capital Partners LP


Date: February 13, 2008         MAGNETAR CAPITAL PARTNERS LP


                                By:  /s/ Alec N. Litowitz
                                     -----------------------------
                                Name: Alec N. Litowitz
                                Title:   Manager of Supernova
                                Management LLC, as General Partner
                                of Magnetar Capital Partners LP

Date: February 13, 2008         SUPERNOVA MANAGEMENT LLC


                                By:  /s/ Alec N. Litowitz
                                     -----------------------------
                                Name: Alec N. Litowitz
                                Title:   Manager

Date: February 13, 2008         ALEC N. LITOWITZ

                                /s/ Alec N. Litowitz
                                --------------------





                                                             Page 10 of 11 Pages


                                  EXHIBIT INDEX


Ex.                                                                     Page No.
---                                                                     --------

A.   Joint Filing Agreement, dated February 13, 2008 by and among
     Magnetar Financial LLC, Magnetar Capital Partners LP, Supernova
     Management LLC, and Alec N. Litowitz...........................          11






                                                             Page 11 of 11 Pages



                                    EXHIBIT A

                             JOINT FILING AGREEMENT

           The undersigned  hereby agree that the statement on Schedule 13G with
respect to the Common  Stock of Grill  Concepts,  Inc.  dated as of February 13,
2008 is, and any  amendments  thereto  (including  amendments  on Schedule  13D)
signed  by each of the  undersigned  shall  be,  filed on  behalf  of each of us
pursuant to and in accordance  with the  provisions  of Rule 13d-1(k)  under the
Securities Exchange Act of 1934, as amended.


Date: February 13, 2008         MAGNETAR FINANCIAL LLC

                                By: Magnetar Capital Partners LP
                                       As Sole Member


                                By:  /s/ Alec N. Litowitz
                                     ----------------------------
                                Name: Alec N. Litowitz
                                Title: Manager of Supernova Management LLC, as
                                General Partner of Magnetar Capital Partners LP

Date: February 13, 2008         MAGNETAR CAPITAL PARTNERS LP


                                By:  /s/ Alec N. Litowitz
                                     ----------------------------
                                Name: Alec N. Litowitz
                                Title: Manager of Supernova Management LLC, as
                                General Partner of Magnetar Capital Partners LP

Date: February 13, 2008         SUPERNOVA MANAGEMENT LLC


                                By:  /s/ Alec N. Litowitz
                                     ----------------------------
                                Name: Alec N. Litowitz
                                Title: Manager

Date: February 13, 2008         ALEC N. LITOWITZ

                                /s/ Alec N. Litowitz
                                --------------------