The Internet allows us to participate in large-scale collaborative projects, say Clay Shirky in the new book Cognitive Surplus. “We used to spend this time watching television, now we are migrating to the internet where our leisure time can be put to good use.”

“We can design services and institutions that rely on that resource in ways that we couldn’t before — from charities to higher education to medical research. The central example I use in the book is Wikipedia because it’s the oldest, the largest and the one everybody knows. Wikipedia has taken 100 million hours of human thought to develop — and we have a trillion to spare.”