badabimbumbam
5000 LEDs drilled into 30m^2 worth of plywood, wrote a kernel driver to present the LEDs as a frame buffer on an RPi with Chromium, we (small team) mounted whole thing onto concrete slabs standing in a lake. Another RPi receives SMS text messages using a JS script to decode GSM PDUs with Unicode that are ultimately rendered on the LEDs. Nice graphics are added on top if you write something sweet for example.
A device to virtually switch an SD card out of an RPi and onto a host computer so you can remotely format the SD card and reboot the RPi.
A crawler versus human detector that is a bit simpler than those normally are.
Lots of projects that get tossed because they require expertise outside of my own area. I'm quite bad at finding other tinkerers to cooperate with, unfortunately.