I'm one of the co-founders of PowWow. We're a lot like GoInstant — in fact their demo video does an even better job than ours does of explaining the concept to a layperson. It's interesting that while their product and ours have very similar use cases, the technology stack is completely different. They have a browser-within-the-browser, while we have an interaction layer over the OS — and we both do crazy hacks to make multiple-mouse live collaboration work. We've met the GoInstant guys, and they're an awesome team with a great product, and we're definitely fans of theirs.
That's great hacking guys.
I am waiting for the Windows version, where i think you'll have a hard time escaping the "only one window has focus" dogma.
Btw, if you need beta testers i am here.