PalTalk operates through a Windows desktop client and has already proven itself very scalable. It uses GAIM to create a consolidated buddy list across AIM, Yahoo Messenger and ICQ. The company says that its 4 million users often have 5,000 chat rooms open at any given time. The largest room they've had open at once included 3,000 people. Cringe-radio stars Opie and Anthony use PalTalk for their chat room and regularly interact with between 1 and 2 thousand people at the same time. I asked the people behind PalTalk how that would be logistically feasible and they said there was a lot of hand-raising going on.