Clay Shirky: "Cognitive surplus (...) represents the ability of the world's population to volunteer and to contribute and collaborate on large, sometimes global, projects (...) The world has over a trillion hours a year of free time to commit to shared projects. (...) Now, that free time existed in the 20th century, but we didn't get Ushahidi in the 20th century. (...) The media landscape in the 20th century was very good at helping people consume. (...) But now that we've been given media tools the Internet, mobile phones -- that let us do more than consume. (...) We still like ...