Slightly off topic but possibly of interest nonetheless..
DIY PSX to MIDI adapter (how to build).
DIY MIDI controllers
using PIC microcontrollers and Basic Stamps.
Yost Engineering make a nice little USB/midi/serial servo controller - it's basically a little board whcih can control 16 or so servos. You can daisy-chain boards together to control about 255 servos per usb etc... quite impressive stuff. There's actually an interview with a visualist about how he used it to control cameras and all sorts of groovy stuff. I've got the usb one (rather than the midi) and that gets programmed via an active x component so you can do it from vb etc.