A series of lectures are available as webcasts on Search Engines: Technology, Society and Business, University of California - Berkeley. And if fact see all sorts of courses at Berkeley that make available webcasts.
This is great. I just love when the internet is actually provides great content to people all over the world, that had no reasonable way to get the material previously.
The webcast of Sergey's Views on Search, Google, and Life (Sergey Brin Co-Founded, Google).
Another great place for podcasts is IT Conversations.