An Online Peer Instruction Tool

This video shows peer instruction in action in a classroom in India. Its basic instructional cycle is:

The instructor poses a multiple-choice question.
Each student votes for an answer.
Students discuss their thinking with their peers.
Students re-vote.
The instructor reveals and explains the correct answer.

This technique works better than either someone talking in front of the class or a recorded video. The reason is the discussion phase: it gives learners a chance to find out how other people are thinking, which in turn allows peers to correct each other's misconceptions.

Moodle, Blackboard, and various MOOC platforms don't support that kind of interleaved discussion, and neither do tools Skype. In particular, their voice and chat tools don't directly support transitions between:

one-to-many broadcast, in which the instructor is presenting to the whole class, and
many few-to-few discussions, in which learners talk amongst themselves.

I'd like a tool that would let the moderator toggle between these two modes so that the group doesn't lose a minute or two making each transition. (I think this would be useful for meetings in general, not just for teaching.) Discussion groups could be set up in a bunch of ways (learner's choice time, moderator-assigned, randomly matched each), and it'd be nice if the voting was built in and if the moderator could ring a bell or something a few seconds before transitions so that learners weren't cut off mid-sentence. Given WebRTC and some back-end hacking, it seems like a prototype wouldn't be all that difficult to hack together; if you'd like to try, please get in touch.