Parrot A.R. Drone
Today at CES, Parrot unveiled its A.R. Drone, a quad blade helicopter that can be controlled using an iPhone. The drone is controlled by tilting your iPhone in the direction you want it to go. It uses WiFi and has two video cameras, one in front and one below the cockpit. Video from the cameras is broadcast on your iPhone screen.
Not sure about the practicality, but cool toy nonetheless!