I added the video to YouTube, but forget to comment on it here. Basically it's very easy to make all sorts of interesting user input devices if you can get hold of a keyboard encoder. A keyboard is in essence a lot of buttons connected to some electronics that communicates to the computer. A keyboard encoder is just a stripped down keyboard, which allows you to add your own buttons.
In the example below I took a childrens toy and wired it up to control the avatar in second life. For example the accelerator pedal is wired up so that when you press it, the encoder tells the computer that the up arrow key was pressed. Very easy.
As a rule of thumb, if the toy makes a noise when you press/turn/squeeze/shake/whatever, then you can use that as an input. Just find the two wires that go to that part, and connect them to your keyboard encoder instead.