While we are at it, don't forget about http://academicearth.org/ http://academicearth.org/. They've done a great job of wrangling all of these sites together. S

While we are at it, don't forget about http://academicearth.org/ http://academicearth.org/. They've done a great job of wrangling all of these sites together. Something nice about being able to jump from circuit design at MIT to Civil War lectures at Yale in just a couple clicks.