I just learned about a project that is rather exciting to me: Julython. If you are looking for an excuse to write some python, this is a great one.
The idea is to commit at least a little bit every day of July on a python project, preferably one that is open source. You get 10 points for committing to a tracked project for the first time and 1 point for each commit after that on the project. This is interesting because it encourages people to work on a wide variety of projects, as well as encouraging numerous small commits.
The variety of projects side is pretty rad, you can add tracking to forks of projects (so it at least tracks your fork) so you get big points for working on a lot of other peoples projects. Hopefully people who do that, then send a pull request to get their code integrated. I really enjoy the idea that I get lots of points for helping out and getting involved with a many projects.
The numerous small commits side is interesting as well. Some people subscribe to commit early, commit often. I try to but tend to get side tracked and end up with a lot of changes that I then have to split up into their own commits. If I am being lazy and it is a personal project, I might just be lazy and commit it all in one commit. This will encourage me to fix that habit.