Jeff pinged me a couple of weeks ago with a new piece of software he's working on from a company called Userplane. It's an Instant Messenger application with full audio/video features, built it Flash I believe, that requires no client download on your computer. Hence I suppose close to 100% portable.
And of course it supports multi-chat rooms. It's now free... Check it out.
... and I just noticed Jason is playing with it as well...
