Document:

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                                                                   Exhibit 10.13

                                 JOSE LIBERMAN

                                PROMISSORY NOTE

$146,950.00                                             Los Angeles, California
                                                               December 20, 2001

                  FOR VALUE RECEIVED, JOSE LIBERMAN, an individual ("Payor"),
hereby promises to pay to the order of LBI HOLDINGS II, INC., a California
corporation ("Payee") the principal amount of ONE HUNDRED FORTY-SIX THOUSAND
NINE HUNDRED FIFTY DOLLARS AND NO CENTS ($146,950.00), together with interest on
the unpaid balance thereof from the date hereof in the amounts and at the times
specified below until such principal amount shall be paid (whether at maturity,
by prepayment, upon demand, by acceleration or otherwise).

                  The Payor shall repay the unpaid principal balance of this
Note by no later than December 20, 2008. The unpaid principal under this Note
shall bear interest until due and payable at a rate equal to the Alternative
Federal Short-Term Rate published by the Internal Revenue Service for the month
in which such advance was made, per annum (calculated on the basis of a 360-day
year and the actual number of days elapsed), such interest shall be payable by
no later than December 20, 2008. This Note shall not be construed to require
payment of any interest in excess of the maximum amount permitted by law.

                  All payments of principal and interest in respect of this Note
shall be made in lawful money of the United States of America and same day funds
to Payee at such place as shall be designated in writing for such purpose by
Payee.

                  This Note may be prepaid in whole or in part at any time
without penalty or premium.

                  THIS NOTE SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND
ENFORCED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF CALIFORNIA,
WITHOUT REGARD TO CONFLICTS OF LAWS PRINCIPLES.

                                      -1-

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                  IN WITNESS WHEREOF, the Payor has executed and delivered this
Note as of the day and year and at the place first above written.

                                              /s/ Jose Liberman
                                             -----------------------------------
                                             Jose Liberman

Pay to the Order of

_________________________________
dated as of _____________________

LBI MEDIA, INC.
(formerly known as LBI Holdings II, Inc.)

By:  /s/ Lenard Liberman
   ------------------------------------
     Name: Lenard Liberman
     Title: Executive Vice President

                                      -2-EXHIBIT 4.1

     AMENDMENT ("Amendment") dated as of October 4, 2002 between FIBERNET
TELECOM GROUP, INC. ("Company") and SDS MERCHANT FUND, L.P. ("SDS") to that
certain Promissory Note dated as of March 14, 2002 (as amended by the Amendments
dated as of June 14, 2002, June 28, 2002, July 12, 2002, August 13, 2002 and
August 30, 2002, the "Note") by and between the Company and SDS.

     WHEREAS, pursuant to Section 10 of the Note, the Company and SDS may amend
the Note; and

     WHEREAS, the Company and SDS wish to amend the Note.

     NOW, THEREFORE, the parties agree as follows:

     Section 1. Definitions. Capitalized terms used and not otherwise defined
herein shall have the meanings ascribed to such terms in the Note.

     Section 2. Agreement to Amend. Pursuant to Section 10 of the Note, the
Company and SDS hereby agree to amend the Note as provided herein.

     Section 3. Amendment.

          (a) Section 1(a)(i) is hereby amended and restated in its entirety to
     read as follows:

          "October 18, 2002;"

          (b) Section 4(c) is hereby amended and restated in its entirety to
     read as follows:

          "the Proposed Financing shall fail to have been consummated by October
     18, 2002; or"

     Section 4. Governing Law. This Amendment shall be governed by and construed
in accordance with the laws of the State of New York, without giving effect to
the choice of law provisions.

     Section 5. Successors and Assigns. This Amendment shall bind and inure to
the benefit of the parties and their respective successors and assigns,
transferees, legal representatives and heirs.

     Section 6. Headings. The headings of this Amendment have been inserted for
convenience of reference only and shall not be deemed to be a part of this
Amendment.

     Section 7. Entire Agreement. This Amendment and the other writings referred
to herein or delivered pursuant hereto contain the entire agreement among the
parties hereto with respect to the subject matter hereof and supersede all prior
and contemporaneous agreements and understandings with respect thereto.

     Section 8. Counterparts. This Amendment may be executed in any number of
counterparts, and each such counterpart shall be deemed to be an original
instrument, but all such counterparts together shall constitute but one
agreement.

                                    * * * * *

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IN WITNESS WHEREOF, the parties have executed this Amendment as of the date
first written above.

FIBERNET TELECOM GROUP, INC.

By: /s/ Michael S. Liss
    ------------------------------
     Name: Michael S. Liss
     Title: President and Chief Executive Officer

SDS MERCHANT FUND, L.P.
By: SDS Capital Partners, LLC
Its: General Partner

By: /s/ Scott E. Derby
    ------------------------------
    Name: Scott E. Derby
    Title: General Counsel<PAGE>

                                                                     Exhibit 4.1

INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

$0.01 PAR VALUE                                                     COMMON STOCK

       Number                                               Shares

                     PLAINS EXPLORATION & PRODUCTION COMPANY

                                                                           CUSIP

THIS CERTIFICATE IS TRANSFERABLE             SEE REVERSE FOR CERTAIN DEFINITIONS
     IN NEW YORK, NEW YORK
        OR HOUSTON, TEXAS

This Certifies that

is the owner of

FULLY PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK, PAR VALUE $0.01
PER SHARE, OF

                     PLAINS EXPLORATION & PRODUCTION COMPANY

transferable on the books of the Corporation by the holder hereof in person or
by a duly authorized attorney upon surrender of this Certificate properly
endorsed. This Certificate and the shares represented hereby are issued and
shall be held subject to all the provisions of the Certificate of Incorporation
and Bylaws of the Corporation and all amendments thereto, to all of which the
holder by acceptance of this Certificate assents. This Certificate is not valid
unlesscountersigned by the Transfer Agent and registered by the Registrar.
Witness the facsimile seal of the Corporation and the facsimile signatures of
its duly authorized officers.

                            [SEAL]                     Dated:

-------------------------------------  COUNTERSIGNED AND REGISTERED:
President                              American Stock Transfer and Trust Company
                                                                  TRANSFER AGENT
                                                                   AND REGISTRAR

                                       By:
-------------------------------------     --------------------------------------
Secretary                                                   AUTHORIZED SIGNATURE

<PAGE>

                     PLAINS EXPLORATION & PRODUCTION COMPANY

     THE CORPORATION IS AUTHORIZED TO ISSUE MORE THAN ONE CLASS OR SERIES OF
STOCK. THE CORPORATION WILL FURNISH WITHOUT CHARGE TO EACH STOCKHOLDER WHO SO
REQUESTS A STATEMENT OF THE POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE,
PARTICIPATING, OPTIONAL OR OTHER SPECIAL RIGHTS OF EACH CLASS OF STOCK OR SERIES
THEREOF OF THE CORPORATION, AND THE QUALIFICATIONS, LIMITATIONS OR RESTRICTIONS
OF SUCH PREFERENCES AND/OR RIGHTS. SUCH REQUEST MAY BE MADE TO THE CORPORATION
OR TO ITS TRANSFER AGENT.

     The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:

<TABLE>

<S>       <C>                                <C>                     <C>
TEN COM - as tenants in common               UNIF GIFT MIN ACT       -  _______   Custodian _______
TEN ENT - as tenants by the entireties                                  (Cust)              (Minor)
JT TEN  - as joint tenants with right                                   under Uniform Gifts to Minors
          of survivorship and not as                                    Act _________________________
          tenants in common                                                       (State)
                                             UNIF TRANS MIN ACT      -  _______   Custodian _______
                                                                        (Cust)              (Minor)
                                                                        under Uniform Transfers to Minors
                                                                        Act _________________________
                                                                                  (State)
</TABLE>

     Additional abbreviations may also be used though not in the above list.

     For value received,                                     hereby sell, assign
                         -----------------------------------
     and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER
   IDENTIFYING NUMBER OF ASSIGNEE

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

--------------------------------------------------------------------------------
Please print or typewrite name and address including postal zip code of assignee

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                                                                          Shares
------------------------------------------------------------------------
of the Common Stock represented by the within Certificate, and do hereby
irrevocably constitute and appoint

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

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Attorney to transfer the said stock on the books of the within-named Corporation
with full power of substitution in the premises.

Dated, ____________________

                              Signature:
                                        ----------------------------------------

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

                              --------------------------------------------------
Dated, ____________________   Notice: the signature(s) to this assignment must
                              correspond with the name(s) as written upon the
                              face of the certificate in every particular,
                              without alteration or enlargement or any change
                              whatever.

SIGNATURE(S) GUARANTEED:
                        --------------------------------------------------------
                        THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE
                        GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND
                        LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN
                        AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM),
                        PURSUANT TO S.E.C. RULE 17 Ad-15.

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