I gather I'm late to the game here, as it was rated on CNN's top 50 sites of 2009, but this is a really cool site. I'd run into Yale's free online video courses a couple years ago. These are not simplified public outreach courses designed for non-students, they are complete college courses by highly rated lecturers which are filmed while being taught and then made available as a whole on the web.
AcademicEarth aggregates those Yale courses along with more video courses from other top level universities. There are currently about 130 courses available.