Not sure if referred to in this section already but the past public lectures at PI are available to watch online and Fay Dowker (been to talk to us a couple of times on theoretical physics - quantized spacetime ) is doing one on 2/11/11 not sure if streamed live but will be available to watch shortly afterwards.
http://www.perimeterinstitute.ca/en/Outreach/Public_Lectures/Public_Lectures/