THIS is a really interesting site put up by UCSF. It's a series of resources targeted toward medical students. Many of the links only work if you are local to UCSF, but a lot of them are usable by the general public. There is a heavy slant toward first and second year basic science material. Nevertheless, it's an interesting site. I wish more medical schools would go this route - I suspect it will become more and more common in the coming years.