Sramana Mitra has articulated a formula to explain the diference between Web 2.0 and Web 3.0 – this a nice encapsulation of a complex set of ideas!

“3C = Content, Commerce, Community 4th C = Context P = Personalization VS = Vertical Search

This, I submit, is the formula for the future: Web 3.0 = (4C + P + VS). “

via Aide-mémoire