Just a fun and easy way to annoy someone, play a game, or shoot it into a recycling box. They can actually "shoot" pretty far away.
Step 1: Get a Water Bottle
Get a cap and put it between your thumb and middle finger. Push your middle finger out really fast and the cap should fly out! It takes a few tries but you can "shoot" it pretty hard and accurately. Though it does work with other caps water bottle caps work the best.