GTalk gadget has added group chat and having tried it recently, I have to say that it’s pretty neat.
The web interface version is done in Adobe Flash, which makes the links that come up kind of annoying in browsers like Safari since you can’t open the links in a new tab or what not. But otherwise, it’s a decent chat room piece just like most decent rooms. You can invite anyone with a gmail account to join (specifically, Gtalk). There are a couple weird things that happen with at least Safari. Beeps occur sometimes out of the blue for each message, then they go away. Not really sure why that is, but it’s definitely strange that it’s intermittent.
Overall, it was a pretty nice experience although it’d be better if it was directly integrated into GTalk and Jabber, since that’s what makes it so nice in AdiumX for chatting on AIM and Yahoo IM chatrooms.