We've got MIT's project:
ocw.mit.edu/OcwWeb/web/home/home/index.htm Then we have OpenCourseWare, which includes dozens of colleges around the world:
www.ocwconsortium.org/ These are not online schools. These are merely class materials republished for the Internet. However, they grant you access to lecture notes, readings, and assignments from some good schools, in technical and not so technical subjects. MIT's stuff includes English classes focusing on consumerism and the media, for example, as well as their many offerings in engineering.
I could imagine some young people who aren't part of the university system deciding to use one of these courses to organize a study group.
I'm currently reading through MIT's Intro to Programming myself.