Old news for many, but a really great source for education via YouTube videos: Khan Academy
Sal gives a presentation on the Khan Academy, how it started and what sets it apart and challenges the notion that free is somehow by definition less valuable than very expensive, and that live is always and necessarily better than video. Plus some heart warming user feedback.
Sal Khan at Gel 2010 (founder, the Khan Academy) from Gel Conference on Vimeo.