Back in July, Microsoft introduced Project Tuva, an online video player which will eventually host a variety of science content, free for all. The player is indeed very nice, allowing users to take notes onscreen while watching, enabling optional expert commentary, and showing closed captioning throughout. The only catch is that you have to install the Microsoft Silverlight browser plugin (similar to Adobe's Flash plugin) -- it's free, and you might already have it installed (it's also used for popular video features like Netflix Streaming).
So Project Tuva starts with the Messenger Lectures by Richard Feynman, a classic lecture series about physics aimed as a general audience, delivered in 1964 and later published as a book called The Character of Physical Law. The lectures introduce a variety of basic physics principles, and are similar to what you'd get as an incoming student at college -- except they're delivered by Richard Feynman, famous for his wit as well as his science chops. Anyway, without further ado, here's the link: Richard Feynman's Messenger Lectures. I've also included a brief intro from Bill Gates below, just to pump you up before getting your science hat on.
Once again, the link to the lectures: Richard Feynman's Messenger Lectures. If you don't want to just start on the first lecture like everybody else, I recommend the fourth lecture: Symmetry in Physical Law.