This is a talk given at the Web 2.0 Expo by Clay Shirky that I found very enlightening. He starts out with a very oblique approach to the problem, but the end result really makes you think about the revolution that's going on with regards to blogs and social networking. The talk is 15 minutes long. If you want to jump ahead, go to about 3:00 and start there.
My time comes from TV. I don't watch it at all any more. Where does your blogging time come from?