If you are into wearable electronics and 3d printing you can combine them with this type of project. One of my friends made cycling jacket with hand gesture activated direction blinkers. With 3d printer, GEMMA controller and NeoPixel LEDs from Adafruit you can make this cool coat buttons.
Detailed build manual on Adafruit learning system:
http://learn.adafruit.com/neopixel-coat-buttons/
http://www.thingiverse.com/thing:226407
