Has anyone here tried this cool programming game?
Robocode
Basically you use Java to program a virtual arena robot, which you can then upload and battle against other people's robots.
It's quite fun.
I'll post a bot once I get a respectable one together.

I know Repsharpshooter toys around with it, I tried downloading it, but didn't know what to do with the files

I used it for a while, and yes, it is pretty cool. It's not really meant for most people however, since you have to not only be able to program in Java, but you also have to understand some higher concepts such as callback functions.