KQED, the monster public television and radio station for Northern California, is beginning a new project on March 15th called KQED Learn (I assume it’s open to any school anywhere).
You can sign-up for information on the launch here.
The site exists now for what I assume to be teachers and students who were testing it out.
It looks like it could be a very useful tool. I’ve embedded a video below that explains it further.