I have yet to try mIRC, but that's because I dont' know if there's a Mac Client of it. My proposal is this (which can be some sort of short term solution):

People can simply post a thread called "Chat" with the date and time (so people know when it's active), then fire up AIM and invite themselves into a Buddy Chat called "GuitarTricks."

As people see the thread they can invite themselves into the room. Since it's not officially part of GuitarTricks.com there's no need for moderation, and if somebody does decide to get obnoxious, well the "Ignore" button does a wonderful job of fixing the problem. Also, AIM is a widely used service and supports all kinds of operating systems making it the most accessable chat out there.

[Edited by Raskolnikov on 03-02-2002 at 05:39 PM]