Tux Typing is a game in which you have to control the penguin attending to different letters appearing on screen. It's raining letters and you have to press the given keys to move the penguin in the correct direction.
The other game is similar, although the goal is to eliminate the drops falling down. The correct way to eliminate them is to press the correspondent letter.
By this way, you'll learn typing while playing, your speed and accuracy will be improved and you won't have to work hard to do it.
Para Mac OS X 10.4 o posterior.