If you want to improve your typing skills this would be the way to do it. Typing of the Dead combines a zombie game with a typing tutor. Needless to say, this would have you typing like a champ in no time! Blasting zombies, saving people, and typing silly phrases makes for an excellent combination of an educational-action game. Unfortunately I could not find an online flash version of the game and downloads for it looked sketchy. Try to play at your own risk.
If this interests you there is more info on it at Wikipedia.