Chomp

This nifty little freeware programme plays the game chomp against you. You have to avoid finishing a rectangular chocolate bar as you take turns to eat rectangular bites from the bottom right hand corner.

There is nothing to install (or uninstall), just run the exe. There are different difficulty settings and you can set how long the computer is allowed to think for, how big the initial bar is, whether sound is played and a few more options.