If you have a java capable phone, use a java irc midlet like jmirc.
http://jmirc.sourceforge.net/
For Series 60 there are native clients. 3rd ed. users can use mirggi,
www.mirggi.net, 1st and 2nd editions use wirelessirc,
http://mobileways.de/M/1/4/0/
Webchats for IRC should be used as a last resort only, a real client is always nicer and better. :-)