I was chatting with someone this morning about this seminar, and realized and enormous assumption that I made when setting up and writing the discussion questions: that we'd be talking about on-demand video, forgetting entirely about videoconferencing.
Have you used much video conferencing? What preparations do you make? What does it do well? How does the dynamic in the room change if there is a combination of f2f and online participators?
One barrier that I've run into is the very real issue of hardware: computers that are too slow, that are too locked down, or bandwidth that just can't handle the stream. Consequently, I'm cautious about trying or recommending video conferencing as a communications method with a large reach. That said, we have conducted meetings with Skype with some success.