Google has a regular internal lecture series on mostly technical topics with guest speakers and some of their own employees. This is their TechTalks Series and the best part of it is that you and I can see them too. They record and digitize the talks (close to 300 of them to date) and make them available on Google Video, using a consistent tag on each one so you can easily search for them and see if any interest you. The link above will do the search and show you all the videos so far.
Some of the titles that caught my eye:
Note: I’m not endorsing any of these, I haven’t had a chance to view them yet. They just looked interesting to me.