Der Schreibtrainer - 10 Finger schreiben
That German software teach you to type faster with all 10 fingers.

Drum machine keyboard B
Play the Piano Drunk Like a Percussion Instrument Until the Fingers Begin to Ble

Tic Tac Total
Entertaining kids game that gives mental addition practice.

R Decode
This program by WorkHorse Games decodes the resistor color bands for you.

WordQuiz
A flashcard program for learning vocabulary and terminology