Yesterday, I had a fascinating lunch with some very bright folks from the Gates Foundation. In addition to public health, the Gates Foundation appears to be ramping up its activities in education. A key topic at the lunch was the impact of the web on education. The discussion really helped clarify my own thinking about what the critical missing element is (at least so far): scale. Scale on the web is unlike anything that we have seen before. Facebook recently announced that they crossed 300 m...