One time I was informally sitting in on a Quantum Mechanics graduate course (I had already taken the course but wanted a refresher). One of the students in the class noticed this and, tounge in cheek, said "Hey, he's learning for FREE!".

I had the same feeling when I stumbled across the Berkeley Computer Science podcasts (on iTunes).

The CS162, Operating Systems and Systems Programming is, IMO, very good (though I have nothing really to compare it to as I never took this course ... but have taken enough courses to know a good lecture when I hear it!). Obviously you won't gain as much as you would by taking the course but if you already know how to program, etc., this can help you see under the OS hood.

Remember back when the internet was new and it was supposed to be a channel for all sorts of educational things like this (I think people probably thought the same about TV)? It's nice to know that there's still some high quality educational material available out there on the 'net (actually, on TV too if you leave it on The Science Channel).

The RSS URL is
[webcast.berkeley.edu...]

Or search for Berkeley Computer Science or something like that on iTunes.