Yea, I used to be all about ICQ, those Chat Rooms that required the I-Chat Pluggin, and then AIM. Slowly the people I talked to online are no longer online or no longer an interest to talk to for the most part.
As for breaking the habbit, maybe come up with a new name and import the buddy list to it. You can be online but nobody will see you and talk to you. Then it will slowly become less and less interesting to be on and on the ocasion you just must speak to someone you could always switch back. I dunno probably wouldnt work but its an idea.