Clay Shirky looks at Cognitive Surplus; the shared, online work we do with our spare brain cycles. While we're busy editing Wikipedia, posting to Ushahidi (and yes, making LOLcats), we're building a better, more cooperative world. Shirky talks about how we're at "the end of coach potato era"; there are "over a trillion hours of free time a year" and we can use it make the world a better place.