This crams a Raspberry Pi model A into a Holga 120 case, and adds a hardware board to the GPIO which controls the shutter, has the option of an external trigger, mode selector and a flash trigger output. I've also added a filter ring to the case, so additional filters and lenses can be used with the Pi Camera - with the IR version this could lead to some creative photography options (not possible with a normal camera).
Plus it looks satisfyingly hipster too!
I used a slice of Pi board to build a simple control circuit for the Raspberry Pi, along with a python script which starts when the Pi is booted up. As well as the 3 input switches and 2 LED outputs the control board had space to add a real time clock module (I used Adafruit's since it was supported with a nice set of instructions). Photos taken are date stamped and can be downloaded when the camera is within range of WiFi.