Learning to touch type is one of the fastest ways to improve your productivity. Mika's Touch Type Trainer is a program designed for to improve your typing speed through the use of children's stories.
The interface is very basic and it's not exactly flashy in the graphics department but it gets down to business quickly and if you've got an aptitude for it you should see some rapid improvements. The program is based around 6 stories including such classics as The Wizard of Oz, Alice in Wonderland and Alice Through the Looking Glass. The program was originally a smash hit in Japan although I suspect this is a stripped down version of it for free. The themes of the stories obviously mean this is a suitable program for children and beginners and it's a very lightweight program that you could even carry around on a USB stick easily. The one major problem with this program is that it has been very badly translated from Japanese to English so parts of the interface, and especially the instructions are difficult to understand.
Mika's Touch Type Trainer is an unusual touch typing teacher which attempts to reach beginners and children although be prepared to struggle with the translations.