The USB missile launcher was fun and taking the concept to another level is the USB Airsoft Turrent. Modded by Jared Bouck at Inventgeek a simple USB based foam missile launcher base and an Airsoft gun were merged to make the USB Airsoft Turrent. The gun shoots plastic BB with a velocity of 250 feet per second which is powerful enough to leave healthy welts on unsuspecting targets.

The total project cost for the USB Airsoft Turrent was $ 70 you can surely unleash the geek in you and add a webcam or a cheap laser pointer for added fun.

More info here.