I just listened to this discussion by Jonah Lehrer on Fora.tv about how your brain works to solve problems, that there is a part of your brain that does the problem solving, a few cells in your right hemisphere it turns out, that you can only access if you're not directly focused on the problem.
It sounds really unlikely, I know—but I also know that this is definitely my experience, that when I'm working on writing a piece, a science piece that is, I often need to distract my brain by playing a game before I can complete what I'm doing. Sudoku, or Babble, or Cryptoquote, or JigZone. Just one of them and I can get back to work. In the past I've always felt guilty about this—I only have a certain number of hours to actually crank out a new science piece and the game-playing has seemed like a waste of time. I've always done it, though, especially just before the final read-through. I don't think I'll feel bad about this any more.