Combines Arduino Uno and a breadboard in one compact box.
Unlike jasonwelsh's folding arduino lab it has no storage for parts and you can't keep a shield on the arduino.
That's because it is meant to be used with something like the Sidekick starter kit (that's where my breadboard came from).
There are magnets to keep it closed while carrying.
If you would like to change something, I've included SolidWorks files for the parts.
I created this thing because I needed a box that wasn't so bulky because I carry it to school everyday.
The parts have about 0.5 mm play to allow for some inaccuracy in printing (it worked fine for me).
After printing drill the holes marked in the Arduino side for mounting the Arduino (I used 2.5 mm screws).
The magnets have to be about 3mm high and 6mm diameter. You can get them from geomag toys by cutting the magnets out.
For the hinges use a 1mm wire (for instance paperclips) and push it in. If your wire doesn't fit you can try cutting it with sidecutters and twisting the cut edge in.
Arduino piece is upside down.