I came across this in Peter Diamandis’s Abundance: The Future is Better Than You Think:

“Wikipedia took one hundred million hours of volunteer time to create,” says [Clay] Shirky. “How do we measure this relative to other uses of time? Well, TV watching, which is the largest use of time, takes two hundred billion hours every year—in the US alone. To put this in perspective, we spend a Wikipedia worth of time every weekend in the US watching advertisements alone. If we were to forgo our television addiction for just one year, the world would have over a trillion hours of cognitive surplus to commit to share projects.” Imagine what we could do for the world’s grand challenges with a trillion hours of focused attention.

Get off your couches, people!