Typing lessons/games online for free that are actually fun?

I've played some online, but they get boring quick. I'm looking for a website that will keep me interested so I can improve my typing skills.|||try some cool typing games on http://www.swfplay.co.uk/|||There's a game on facebook that's called typing challenge or something like that. It trys to get you to see how fast you can type while still being accurate.