The eee pc comes preinstalled with Pidgin, which is a great application for those of you who use msn, aim, gchat, or any other instant messaging service. It combines them all into one useful application.
Its kind of big and clunky. I actually prefer meebo.com.
It looks a bit nicer, and it is portable anywhere. The folks at meebo have integrated a ton of great features, that I hope will all begin working on the eee as well.... For example they should have video chat going... I don't video chat, so it doesn't concern me, however if the folks at eeeuser.com ever figure out how to get adobe flash to recognize the eee's webcam, you are in luck!