Starting some script when gnome2 comes up

[dballester kernpharma com]

Hi:
     Sorry if this is a newbie question, but I'm lost. I wanna start some
commands ( open office quickstart ) at least one time when gnome comes up,
after gdm login. Where can I put the shell? I suppose that all gnome
related stuff at start up is executed from a shell script, or at least,
calling a program. Can I put my own script at the end of this suppoused
program or script?

As always, TIA