I already pointed to Scitable on my other weblog, and I thought I would here too. It’s a new education oriented site put out by Nature which is currently focused on genetics. The topics section is pretty good for a more-deep-than-Wikipedia but not-quite-a-research-paper level stuff. They do have a “feedback” option, but I really think they might benefit from having a comment feature which can be hidden. There’s a lot that can be learned about a subject from the various debates people have about specific terms (this sort of feeback occurs in Wikipedia discussions).
