I'm a daily user of 37Signals "simple software" packages Backpack and Basecamp. The company is one of my favorite developers, as I've commented elsewhere. They've just launched Campfire, a secure group chat software that requires nothing other than access to the net and a web browser (IE6, Firefox or Safari only).
Campfire allows you to quickly create individual chatrooms that are permanent - with their own permanent url. You can browse previous chats - or do a search on them. Check out Campfire here and sign up for a 30 day trial.
And drop me a note if you want to have a chat.
[HT: O'Reilly]
UPDATE: Stowe Boyd has an interesting take on Campfire - positive with qualifications.
Technorati Tags: 37signals, Campfire, group chat, simple software, web software