Heh, many years ago when I was in school, the internet was small and cute and grey and ICQ was all the rage... I'd leave it on 24/7. But then there was only a couple of close mates on it anyway.

Nowadays I don't like IMs much. It's not like I'm completely anti-social, but sometimes it's annoying when I'm trying to browse the web or write forum posts and there are a bunch of people bugging me with small talk. I could just leave it on 'Busy' but I'd be inclined to leave it on busy all the time so instead I just don't bother running it

If people want to "chat" and make small talk there is always facebook/bebo/etc or even email. Those who are likely to have an actual purpose for contacting me already have my mobile number, so IM is pretty much redundant and mostly annoying.