I meant to mention this a few weeks ago, but I've been off gallivanting around New Zealand.
Jonathan Tweed from the BBC has finished putting together videos from all of the Teach-In sessions. You can get them (in various formats) from his Blip.tv account.
One small caveat. The batteries on the radio mike ran out about fifteen minutes before the end of the last session, so we have no usable audio for that time. We'll know better next time.
Thanks to Jonathan for all the work he's put in on this. I'm not sure I'd want to spend as long as he has listening to my voice!