I love this type of code on code violence. Our machine learning professor had us do several of these in college. Another cool one is Robocode, from IBM alphaworks: http://www.alphaworks.ibm.com/tech/robocode
Another post pointed me at the Netflix prize http://www.netflixprize.com/ the other day. Got me to thinking what other programming contests one could make money from. Bit of a long shot, but then a start up can be too.