I'm on AIM pretty much all the time (go ahead, check-- my name is AnilDash) but it's annoying how each new version of AIM includes more ads, more useless stock tickers (that default to on...? Duh.) and crap like that. So I'm going to try out Novell's AIM-compatible instantme and see how I like it.
At the very least, I know it doesn't have any ads.