Launching applications at startup

Hi Guys,

I'm looking for a way to automatically launch an application when a user
logs in (Gnome 2.2).  I've looked at default.session which nearly does
what I want but fails for two reasons:

1) If user already has their own gnome session profile it'll be ignored.
2) PITA to add/remove entries safely from default.session when
installing package from an RPM.

Any other ideas?

Cheers,
Pete