Fun to Type (This is a favorite of the students!)
http://www.powertyping.com/rain.shtml
http://www.powertyping.com/baracuda/baracuda.htm
http://www.bbc.co.uk/schools/typing/
http://www.learninggamesforkids.com/keyboarding_games.html
http://www.typingtest.com/games.html (Typing Towers)