I have what I think is a very unique idea for a contest and I'm providing a link to a recent submission that will explain it... instead of reprinting the whole thing. Comparing the submission to another one by Tick will cover the whole concept.
If you've ever wanted to make a difference but found it hard to believe that one person could... check out the Kiva Team Caedes discussion thread and discover that anything is possible.
Here's the link.
-Nik