You can see if people are hanging out in the #boo channels:
GimpNet network: irc://irc.gimp.org/boo
Codehaus server: irc://irc.codehaus.org/boo
If no one is there, please try the Mailing Lists.
IRC clients
There are many popular IRC clients out there.
On Linux there are clients like Gaim, XChat, BitchX.
On Windows there is Gaim, Trillian, X-Chat, mIRC.
IRC bots
If you are interested in accessing IRC from a boo script, check out IRC libraries like SmartIrc4net (used by Gnosmirc) or Thresher.