Available on September 30th, 2011, Gibson Guitar Corp will be offering their Firebird X is a limited 1,800 sets of each color. The guitar is a modern version of the 1960s classic Gibson Firebird. Onboard are built in effects, computer plug-in tech, Bluetooth pedals, an "App store" for developers, and what makes it a robot, the 4th-gen auto tuning feature.
This is a video of the original Robot Guitar from Gibson
The auto tuning feature was first introduced by Gibson back in December of 2007. The aim was to tune the guitar in 15 seconds with a tolerance of 2.5%. The system works by sensing the sound of an open-hand strumming of the strings. Working in conjunction with a piezo-electric saddle for sensing, the head of the guitar tightens each string until the set pitch is reached. Each of the strings is tightened by a its own micro-servo motor. Since a servo has very little torque at low speeds, a gearbox is most likely used.
It can be yours for $5,570 right now. I would recommend going with the older robot guitars, like the version 1 Les Paul for around $1,000 - 3,000.
Eavesdropper