Incredible. I think I'll start with this one http://ocw.mit.edu/courses/electrical-engineering-and-comput... The notes were typed up by students of the class, as part of some obligation/requirement, apparently. Not sure if that applies to the other courses. So much stuff on there to learn, it'd make you weep.

Love the MIT free courses, really learnt a lot from all these materials. I know for sure, I could never get admitted to MIT CS program. Now I just hope all the rest of the top 10 uni does the same too.. Education should be FREE for everyone.

Are there any sites to let people collaborate while working through these courses?

I don't think there are sites that do this currently, but the idea is definitely in the air, so there are probably guys working on it. For example, it seemed something like 3 of the 5 guys from the Google IO VC panel from late last week talked about wanting to fund collaborative educational startups.

EDIT: This is the panel I was talking about ... http://news.ycombinator.com/item?id=1405320

Unclasses.com allows people passionate about learning to connect. Not sure if anyone has started an MIT thread, but that might be a community of learners that would be interested in collaborating together.

I really enjoyed the EECS courses available there.