Doesn't need to be ICQ... its IRC, so Pocket IRC (shareware) or zsIRC (freeware
http://www.pocketpcfreewares.com/en/index.php?soft=1703).
But if you've got other stuff you're supposed to be doing at that time, maybe we could see if there's any alternate times that would work for everyone. Whichever time can get the most people is the one we go with.
As for me, I'm busy in the morning and early afternoon but am free any time after 3pm.