The slides from last weekend's Teach-In are are now available online.
You can also get audio and video of the first session on both Blip.tv and Google video. There's also an RSS feed that you can subscribe to if you want to know when the remaining three sessions are released (over the next couple of weeks). I'm told that this feeds links to "enhanced podcasts" of the presentation - but not being an iGeek I have no idea what that means.
Thanks to Jonathan Tweed at the BBC for the work he is putting in on these recordings.