<PAGE>

                                                                   EXHIBIT 10.25


                                 PROMISSORY NOTE
                                 ---------------

$50,000.00                        Houston, Texas              September 27, 2002


FOR VALUE RECEIVED, on the dates and in the amount so herein stipulated, the
undersigned, Excalibur INDUSTRIES, INC., a Delaware corporation, with its
principal place of business located at 16825 Northchase Drive Suite 630 Houston,
TX 77060 (hereinafter called "Maker"), promises to pay to the order of DAVID N.
RAINS ("Payee"), at 16825 Northchase Drive Suite 630 Houston, TX 77060, or at
such other place and to such other party or parties as the Payee may from time
to time designate in writing, the principal sum of FIFTY THOUSAND AND NO/100
($50,000.00) in coin or currency of the United States of America together with
interest thereon from and after the date hereof until maturity at the rate of
10.0% per annum, payable as it accrues, on the then unpaid principal amount
hereof, but in no event shall the interest exceed the maximum amount of
nonusurious interest allowed from time to time by applicable law ("Highest
Lawful Rate").

         The entire unpaid principal balance of this Note, together with all
accrued, but unpaid interest thereon shall be due and payable on December 27,
2002.

         All past due principal, and to the extent permitted by applicable law,
past due but unpaid interest, shall bear interest at the rate of twelve percent
(12%) per annum. Interest shall be calculated based upon a three hundred sixty
five (365) day year. If this Note is not paid at maturity and is placed in the
hands of any attorney for collection, or suit is filed hereon, or proceedings
are made in probate, bankruptcy, receivership, arrangement or otherwise for
collection hereof, Maker agrees to pay all expenses and costs incurred by Payee
in connection with such collection, suit or proceedings, including without
limitation, attorneys' fees in any amount not less than ten percent (10%) of the
then unpaid principal of and accrued interest on this Note.

         Maker reserves the right to prepay all or any portion of the remaining
principal balance due at any time, and from time to time, without penalty or
fee. However, any such prepayment hereunder shall be applied first to accrued
unpaid interest, if any, owing on this Note and the balance to principal.

         The undersigned, as well as any persons or entities which become liable
for the payment of this Note, hereby expressly (a) waives (i) demand or
presentment for payment of this Note, (ii) protest, bringing of suit or
diligence in collection and/or (iii) any defense on account of the extension of
time of payments; (b) consents to any substitutions, exchange or release of any
security herefor or the release of any party primarily or secondarily liable
hereon; and (c) agrees that (i) the acceptance of late payment(s) hereunder by
the owner and holder hereof, (ii) waiver of any event(s) of default hereunder
and/or any instrument securing or guaranteeing the payment hereof or (iii) other
forgiveness of any other defaults by the undersigned, shall not constitute a
waiver by the owner and holder hereof of any subsequent defaults, late payments
or other violations of the Maker's obligations hereunder and/or in the terms of
any instrument securing or guaranteeing the payment hereof.

         All agreements between the undersigned and the holder hereof, whether
now existing or hereafter arising and whether written or oral, are hereby
limited so that in no contingency, whether by reason of acceleration of the
maturity hereof or otherwise, shall the interest paid or agreed to be paid to
the owner and holder hereof exceed the maximum amount permitted under applicable
law. If, under any circumstance whatsoever, interest would otherwise be payable
to the holder hereof at a rate in excess of the Highest Lawful Rate, then the
interest payable to the owner and holder hereof shall be reduced to the maximum
amount permitted under applicable law, and if under any circumstance whatsoever
the owner and holder hereof shall ever receive anything of value deemed interest

<PAGE>

by applicable law which would exceed interest at the Highest Lawful Rate, then
an amount equal to any excessive interest shall be applied to the reduction of
the principal amount hereunder and not to the payment of interest or if such
excess interest exceeds the unpaid principal balance of principal hereof, such
excess shall be refunded to Maker. All interest paid or agreed to be paid to the
owner and holder hereof shall, to the extent permitted by applicable law, be
amortized, prorated, allocated and spread throughout the full period until
payment in full of the principal of this Note (including the period of any
renewal or extension hereof) so that the rate of interest hereon is uniform
throughout the term hereof. This paragraph shall control all agreements between
the undersigned and the owner and holder hereof.

         THIS NOTE SHALL BE CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE
OF TEXAS AND THE LAWS OF THE UNITED STATES APPLICABLE TO TRANSACTIONS IN TEXAS.

         Any check, draft, money order or other instruments given in payment of
all or any portion of this Note may be accepted by the owner and holder hereof
and handled for collection in the customary manner, but the same shall not
constitute payment hereunder or diminish any rights of the owner and holder
hereof except to the extent that actual cash proceeds of such instruments are
unconditionally received by the owner and holder and applied to this Note in the
manner hereinabove provided.

         IN WITNESS WHEREOF, Maker. has executed or caused this Note to be
executed to be effective as of September 27., 2002.


                                         EXCALIBUR INDUSTRIES, INC.


                                         By:  /S/ Matthew C. Flemming
                                            ------------------------------------
                                                  Matthew C. Flemming,
                                                  Executive Vice President