There's a small party going on over in Freenode, because one of the few 'killer apps' in my view has finally recieved an update. Previously available for the 7650 and 3650, Mobileways have released an updated version of WirelessIRC for the modern smartphone. Expect a review, but by adding in Bonjour, Del.ici.o.us and Twitter support alongside a million custom features means it may take a while!

Author's description:

WirelessIRC v1.00 is a native IRC client for your S60 3rd Edition phone.

Chat with thousands of other people on the Internet Relay Chat or talk on your local WLAN network via Bonjour Local Chat!

WirelessIRC connects you to any IRC network while you're on the move. Be in touch with your friends everywhere at any time.
With the help of WirelessIRC's Auto-Completion of commands, channels and nicknames, you can chat more comfortably and quicker.

WirelessIRC will automatically grab URLs, save them for copy & paste or post them to your del.icio.us account!
Semi-transparent windows let you keep track of various conversations at a glance.

WirelessIRC requires an internet connection - either via WLAN or mobile internet (GPRS, UMTS, CSD, ...)