Maybe you've seen many good Open Source projects that are no longer maintained. One of the many reasons for that may be lack of contribution. In fact, there are many one-man projects out there. Most of any program's users are just that, users, not developers. Nevertheless, average users still can contribute to Open Source programs to make them better.
Find out how:
http://nongeeksight.blogspot.com/2006/09/5-ways-to-contribute-to-open-source.html