Full description/detail here: http://cre.ations.net/creation/printable-jacket-cuff-lights
We've all been there. Fumbling around in a dark parking lot, trying to find the keyhole on the car door or mailbox. Sure, you'd use a flashlight, but who has the room for those bulky outlines?
Granted, the cuff lights aren't the most practical of solutions but they're so cool. They're hidden in your jacket cuffs, nearly invisible and perfectly comfortable, just waiting to be activated with a little sideways pressure.
Also, if it's very dark, you can stun would-be attackers with them. The lights are bright enough to blind and disorient for about 5-10 seconds when eyes are accustomed to darkness.
Kits, preassembled modules, and full assembly/installation instructions are posted on creationsnet:
Long story short, you print them, put in the electronics, and sew them into your jacket. The electronics are removable so you can still wash your jacket.