I built this little midi controller to trigger samples and control a few Pd parameters:

It's based on an old touchtone telephone keypad, a rotary encoder, a two digit LED display, and a USB-based AVR breakout board (the Teensy++). The PC board was hand-etched at home, and it's mounted in a solid white, repurposed jewelry or makeup box, purchased at the Goodwill.

Click the above to view more images, read the brief technical spec, and to download the code and circuit/pcb design artifacts.