There aresomeposts on planet about IRCing with Irssi.
IMHO, one of the greatest thing in irssi is the proxy module. It’s great to be able to use any IRC client you like plus having the benefit of being able to use the running irssi instance in the screen on your server. For example, when my DSL get’s disconnected for some odd reason while I’m at work, I can happily use the irssi (with running proxy) in a screen session without any problems. Irssis proxy module is really worth a try! 🙂