http://go.icq.com/
Very handy when you're away from the comp (or you can't be bothered installing ICQ

) but I seem to have a lot of problems with its stability. Often if I am talking to someone it will open a second (duplicate) window when they reply and from there on all of the ICQ windows are blank and it stops responding.
This is under XP Home, I even had probs with W98SE... I suspect it's a dodgy Java runtime... what do you use? Do you have these problems?