If you want to make the challenge even more intense, you can try a service like Beeminder that'll charge you if you don't commit every day. It can hook into Github, I believe.
The founders actually use this themselves, making a mandatory UVI (user-visible improvement) every day, inspired by pg's advice "startups rarely die mid-keystroke... so keep typing!" See here for more on that: http://blog.beeminder.com/rails/
These are great! I think I've seen Bee Minder before. Honestly, it has helped me out tremendously to just keep committing. I have days where I commit some really trivial bit of code, just to keep things going, but first thing in the morning I'm thinking about what I plan to commit that day. It keeps me focused on my side projects.
https://www.beeminder.com/gitminder
The founders actually use this themselves, making a mandatory UVI (user-visible improvement) every day, inspired by pg's advice "startups rarely die mid-keystroke... so keep typing!" See here for more on that: http://blog.beeminder.com/rails/