Thanks to Gibson's Powertune system, now even tin-eared guitarists can push a button, strum the guitar a few times, and then it's as if a ghost has taken over the machine, turning the tuning pegs until the guitar is accurately tuned. It tunes each string to within .02 cent, which is pretty damn close to perfection. It can tune to the default A440, or it can tune the strings to pitches that are relative to a note of your choice. You can also store a variety of tunings and quickly call them up. Hey, this could really be useful.

It works by using piezoelectric pickups rather than the usual magnetic pickups used on most electric guitars, and these pickups are able to isolate the sound of each individual string. Underneath the pickups is a processor that senses the pitch being played, and sends a signal to the tuning pegs at the top of the guitar's neck to change the pitch until it's all tuned up.

Even though this machine may be perfectly accurate, turning a guitar can be a subtle art, where you can slightly change some of the notes to fit the key in which you're playing. However, for musicians who like to play various songs with the guitar tuned in completely different ways for each song, this technology could be extremely useful. In fact, the $899 it adds to the price of the guitar might seem like a bargain compared with buying two more guitars, each tuned in a completely different way. [Technology Review]