Sensor Board Simulator
We just got one of the Scratch Boards (now called PicoBoards), and it's great. But we noticed on the forums that people are still confused about how it works. This project simulates the board fairly well, so you can kinda play around with it. You can actually use it to prototype Scratchboard apps to see how they may work. The variables at the top of the screen are similar to the sensor values the board creates.
Hold down [H] key and mouseover things to get info on certain parts of the board.