A pair of Canadian university students are raising Kickstarter funds for a USB prank stick, aptly called the Prankstick. The Prankstick is a USB key with a pranking software installed on it. Simply stick the Prankstick in someone's laptop, load the included program, remove the stick and watch hilarity ensue; your victim will return to their computer to find that it's seemingly been taken over by some sort of poltergeist or hacker.
A range of pranks are loaded onto this USB prank stick. They include 'Mouse Move' (causes the mouse cursor to randomly jolt around the screen,) 'Eject CD' (ejects the CD drive at random intervals,) 'Caps Lock' (toggles the caps button on and off,) and 'Backspace' (prompts the backspace key to backspace every five seconds).
The Prankstick is currently only configured to work with Windows, but the inventors are looking to eventually release a Mac-friendly version.