Take it for what it's worth, but here's my pitch: get angry. I find that most of the time when I'm in a funk, I feel completely apathetic. I can't get any work done or stay focused on any problem because I don't feel any emotion toward what I'm doing. It's easy to say 'I don't care.' When that feeling hits, I dig deep into my music library for songs that bring out strong feelings other than depression or sorrow. The happy songs I can't get into, but the ones that have a little more pasion/rage (speaking of which, Rage Against The Machine would be a good one..) really get me going. It's easier to focus when I'm emotionally charged, so turn it up and get mad until you finish. Then you can relax and feel good about dominating the issue. Probably doesn't work for everyone, but I wouldn't share if it didn't help me :)