ethereal is a sniffer, you use it to capture and monitor your eternet.

You start ettereal (and do some easy configing)
You run any irc chat program (I use X-Chat)
then you look at how the irc chat prog does his talk to the irc server..

that way you can do it yourself in telnet..

more on ethereal: http://www.ethereal.com/faq.html

/me has used this to be able to telnet to the MSN servers.. that's a bit harder then irc though couse of the MD5 stuff you'll have to do to make msn chat connect..