http://ocw.mit.edu/courses/index.htm

I've done 3 of the Coursera/Berklee College of Music classes. My problem looking at a list like this is there's too much interesting stuff.

I'm not sure exactly how the MIT system works, though it looks like this page describes it as much as possible:

http://ocw.mit.edu/help/get-started-with-ocw/

And for those of you Matlab nerds, there are a few open alternatives to Matlab. I'm currently giving Octave a trial workout on processing some firearm sound pressure level time histories.