Today, I was introduced to "Scalatron", a kind of virtual robot wars as a platform to teach programmers about Scala. Its a fascinating concept, and appeals to my competitive nature in the programming arena. Additionally, I think I can use this as a virtual world to validate some ideas I have about emergent intelligent behavior.
Watching some of the competitions on youtube, there seem to be a number of ways you can set up the rules to the game. I like this particular one, which introduces food, both animal and vegetable, poison, and predators as part of an environment where you try to prove your bot the best.
If you are looking for an excuse to learn a new language, this may be as good a reason as any!