My IM system of choice:

screen + irssi + bitlbee

http://www.bitlbee.org/
So what does it do?

Just install the program and connect to the BitlBee server with your favourite IRC-client. You will be force-joined into the control channel where root (the bot, your assistant, the bee) will try to help you to get the program working.

As soon as you got your accounts working, you can add users to your contact list and talk to them, just like you normally do on IRC. Open a query, talk to the person in the channel, or even open a group conversation. (But remember IRC is the only true conversation protocol! ;-)
Also check out the screenshots