Kami-Oto is a cardboard based MIDI controller that is on Kickstarter right now. If you like DIY and origami, it might just be worth your while.
BYO origami skills: the Kami-Oto MIDI controller by Yudo is a cardboard device that can be built in half an hour, with connectivity via USB and Bluetooth.
The unit ships with the main board, silicon contact with the cardboard components being the outer shell and keys.
Other than its ephemeral building material, the device works like a standard MIDI controller, with an octave shifting button, function keys for altering MIDI channels and the capacity to sense dynamics.