Self-explanatory title.
The facilities you can go look out for:
Digsby IM client
Pros: works with AIM, MSN, Yahoo, ICQ, Google Talk, Facebook and Jabber
works with Mac, Windows, Linux
Cons: file transfer eats up system process
limited skins
still in beta
IM feeds (consolidate all your RSS and Atom feeds, and be notified through your IM)
Pros: No need to check your feeder. The chatbot does the checking
Cons: Requires one of the designated IMs
Chatbot.org (collection of usable chatbots. I added the one for encarta.)
There we go, some stuff that I have found up till now.