To address a meta-question: I disagree with the people who claim that you shouldn't contribute to a project for any reason other than intrinsic interest in the product itself. Most people, after all, work for extrinsic reasons; it's a normal part of life. There is nothing wrong with contributing to an open source project to improve your programming skills, boost your resume or pay some of your karmic debt to your species for the gift of your life. These are all valid reasons, and all are flexible regarding the specific nature of the project.