I'm pretty fond of MCabber (http://mcabber.com/), a full featured XMPP client with proper Multi-User Chat (MUC) support. I use it inside a screen(1) session, next to irssi.
MCabber looks pretty nice at first glance; thanks for the tip. I'll have to go find a sample config for it before I can actually use it and see if it's any good though.