With the advent of the incessantly beeping and easily concealable Annoy-a-tron, ThinkGeek has ushered in a new era of sophisticated office pranks sure to drive your co-workers bonkers while you snicker silently at your desk. Now the next advanced level in stealthy office joke electronics is ready for your enjoyment. The Phantom Keystroker may look like a harmless circuit board, but it’s actually a devious contraption of unlimited office-based torture. Simply discreetly attach the Phantom Keystroker to any extra USB port on your victim’s computer, no drivers needed. The Keystroker emulates a keyboard and mouse and periodically makes random mouse movements and types out odd garbage text and phrases. A simple jumper setting allows you to choose between either keyboard garbage typing, annoying mouse movements or both. An adjustment pot sets the duration between “events”. We recommend you don’t set it too frequently so as to extend the agony.

Your hapless co-worker pal will think his computer has been possessed or infected by a destructive virus. As he writhes in anger and furiously dials tech support you can rest easy with a job well done. 

Phantom Keystroker - Computer Prank Gadget: [Via] - [ThinkGeek]