If you missed the live stream of John speaking at TEDxIndianapolis yesterday, you can see his talk here, starting at about 16:40 in. He speaks about “The Paper Town Phenomenon” described by the TEDxIND site as thus:

When we think of education as a school-based phenomenon, we do a disservice both to students and to the rest of us. Green argues that we should imagine education as a kind of cartography, and discuss how online communities are helping to build learning maps that will encourage students. From YouTube to tumblr to the Khan Academy, the line between education and entertainment is blurring, and as these tools reach more and more people. The youth of today are quietly becoming the best-informed, most intellectually engaged generation in world history.