http://www.khanacademy.org/index.html

There is a huge set of math and science video lectures at this site. I've watched some of the elementary math ones with my son, but the content goes up to college level and beyond. The ones I've seen are just videos of an electronic blackboard, with voice-over of the lecturer. He speaks clearly and explains well. No frills, but potentially a goldmine of in-depth content.

wow! that's a lot. I put that in my favorites

Great site! Thank you for posting!

Thanks for this!

Cool!!!