the file you need:
http://prdownloads.sourceforge.net/xonx/XFree86_4.2.1.1.zip?download

the project:
http://sourceforge.net/projects/xonx

extract and install it and
then run X11 an then type:

sh /Applications/OpenOffice.org1.0.1/program/soffice

(there is a space after sh !!!)

if this not work type this before:
setenv DYLD_LIBRARY_PATH /Applications/OpenOffice.org1.0.1/program\
:/Applications/OpenOffice.org1.0.1/program/filter:/usr/X11R6/lib

Here is the original description:

Running OpenOffice.org under XDarwin

Hardy Mayer and Ed Peterlin

1. X-windows for MacOS users

This section briefly explains some of the background needed for running the beta
version of OpenOffice.org1.0.1 (OOo) under Mac OS X (10.1 and 10.2).

In addition to a standard MacOSX installation, it may be useful to have the Development tools installed (so that you have access to a gcc compiler and some other useful tools).

You will need a current version of XFree86 and xDarwin installed which you can
download and install from the following sites:

http://www.xdarwin.org
http://sourceforge.net/projects/xonx

The main thing you need from this distribution is the X-server -- a unix program which allows you to launch various applications making use of the X11R6 windowing system --- a standard on most Unix systems, such as Linux, BSD, Solaris, HP-UX, AIX, etc.
Since we do not want X to take over the complete display, we make use of XDarwin, a Darwin interface which allows X applications to run "rootless," i. e., on top of the MacOSX display, though they will look less elegant than standard ``Aqua'' applications (no pulsing blue buttons, etc.).

In principle, one could run OOo directly under XDarwin, making use
of the supplied startup scripts.

From an active xterm:

setenv DYLD_LIBRARY_PATH /Applications/OpenOffice.org1.0.1/program\
:/Applications/OpenOffice.org1.0.1/program/filter:/usr/X11R6/lib

cd /Applications/OpenOffice.org1.0.1/program
sh soffice &