I'm looking for a way to know when a user is available -- similar to how a chat application might know if a user is available by keyboard or mouse activity.

That is, I'd like to run a script when a user first logs in (which might be automatic login as, for example, Ubuntu allows), and when the computer wakes from sleep or "unlocked".
Not sure if this is a Gnome issue or maybe lower level -- like via dpms.

Any easy hooks for doing something like this?

--
Bill Moseley
moseley <at> hank.org