Unhangout is an open source platform for running large scale online un-conference-style events using Google Hangoutsto create many simultaneous small sessions. Think of it like a classroom with infinitely many breakout rooms. We provide a text-based chat experience that can support hundreds of participants chatting or watching a live video stream together. When you want to create more opportunity for participation, you can break out into up-to-ten person Google Hangout sessions that create opportunities for peer learning instead of just top-down information transfer that is typical in large scale online education.
via Unhangout.
This is worth keeping an eye, especially if it manages to tame the wild world of Google APIs a bit to make Hangouts more useful for real events. Unhangout is written in Javascript and is powered by node.js and Redis. You can get the code for this open source project on GitHub at https://github.com/drewww/unhangout.