Clay Shirky has been giving talks on his book Here Comes Everybody — his "masterpiece," per Cory Doctorow — and BoingBoing picks up one of them, from the Web 2.0 conference. Shirky has come up with a quantification of the attention that TV has been absorbing for more than half a century. Shirky defines as a unit of attention "the Wikipedia": 100 million person-hours of thought. As a society we have been burning 2,000 Wikipedias per year watching mostly sitcoms. We're stopping now. Here's a video of another information-dense Shirky talk, this one at Harvard.