Noah at Instructables posts instructions for a mischievous office toy: the credit card grappling hook.
"The credit card grappling hook is a whimsical little project that combines a credit card, some simple hardware, fishing line thread, and a sewing machine bobbin. It's functional for light grappling duties, but is mostly just meant to be used as a toy and for entertainment."
Wish there was a video of this nifty mini-weapon in action...

