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.

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/