The location aware profile switching would be extremely useful; I would also love to know if it is possible.

I imagine time based profiles could be set up with a simple script, if nothing better exists to do it. I thought I read about people setting up scripts to shut off wifi at night, etc, to save battery life -- surely changing profiles wouldnt be much harder.

But at the moment, I have no idea -- because I haven't actually got my n900 yet (hopefully it will arrive tomorrow!)