I promised to point out when it was available, and you can now watch author videos from this year’s National Book Festival. (The same website has video from previous festivals as well, but the science and technology content is not as rich as it was this year.)
Since there’s several hundred videos to wade through, here are the links to the four authors I saw on September 25. I strongly recommend you watch the Petroski video, though anyone familiar with the work of the other authors should enjoy listening to them. You’ll need RealPlayer to view.