If you've ever wanted to learn Chinese or find out about Fluid Mechanics (Who hasn't??) check out this site. It's got links to free video lectures, reference sites, ebooks, documentaries, software, on just about everything you could ever want to know. Well, not everything, but lots of things. I'm not planning on learning about Soft x-rays and Extreme Ultraviolet Radiation anytime soon, but it's nice to know you can check out a webcast from Berkeley or a Wikibook about Lucid Dreaming if you wanted to...