Introduction: Hidden Crossbow
Looks like a crossbow, but technically it's a slingshot. I saw instructions for a BIC pen "Bow and Arrow" on the site and decided to step it up a notch.
This contraption is made to be worn under a loose sleeve, hidden from sight. It shoots the ink cartridge of a ball-point pen. The trigger (a clothespin) is rigged to fire when I flick my wrist back.
The instructable is now up! You can find it here.