Pidgin previously known as ‘gaim’ is a kool multi protocol messneger available for Linux.
You can have your yahoo, gtalk contacts in a single place . The interface is cool without the usual bloat added by other messengers.
PS. On my Fedora core 5 system the application installed correctly but would not start. I found the problem already logged in at the pidgin bug database and the solution also . The problem it seems was that pidgin required a new version of library called lib-purple whereas in fedora core 5 a older version was present. Updated my lib-purple library and then pidgin popped up on the screen with its full glory.