If you are looking for some truly outstanding and often quite accessible materials for lifelong learning, MIT offers its open courseware program at http://ocw.mit.edu where you can find 1600 different classes that you can try on your own. You don't get any credit for these courses (MIT does prefer collecting tuition if they are to grant credits and degrees and the like) but many online affinity groups form around the program where people act sort of like classmates in a completely unregimented open source university. It's kind of like Richard Stallman's "free as in freedom," libertyware concept brought out of just software and applying the notion of information anarchy on an entirely different kind of data. Enjoy, cdh