I’m using an Arduino to control two (maybe more – I haven’t tried yet) AD5204 digital potentiometers. Here’s some info about adapting the digital pot Arduino example to work with daisy chaining.
I made a big red button to replace the Escape key. A museum that I’m consulting for needs this for a touch-screen kiosk that runs Crayon Physics.
I like the little gems of ingenuity and economy of design found inside crappy toys. I was taking apart some electronic toys yesterday, as is my wont. This particular toy had a few neat mechanisms, but I thought this use of rotary encoders and cams was especially cool.