Gibson's Robot Guitar may have gotten off to a head start, but EverTune is here at CES with an automatic guitar tuner of its own that promises to keep your guitar in tune forever. To do that, EverTune makes use of a simple mechanism that relies on springs to maintain the same amount of tension on each string as the tuner post loosens, which should ensure that your guitar won't go out of tune even while playing (something that other self-tuning guitars can't account for). Unfortunately, EverTune isn't ready to announcing anything about availability (or pricing, for that matter), but it saying it will "soon be available on a wide range of electric guitars," and that it'll also be available as an installation kit through select retailers.