msn sucks my ass stupid thing decides to randomly sign me in as online when I'm usually 'appear invisible' (since I don't have it to talk to folks, just so I know when I get new email) fuckity
I use trillian. It follows my every whim, and I can be signed on several IM's at once. But usually I don't want to talk to half those people.
Yeah!^ I use trillian too. It saves your settings so you can actually sign in in invisible mode and see who's online before they see you.