TrueTemperament is a revolution in guitar neck technology, courtesy of Paul Guy Guitars Sweden. Check this out!

With a revolutionary new approach to the design of the guitar's fretboard, True Temperament delivers an accuracy of fret scaling never before achieved in the history of the guitar. Genuine innovation, and a radical new fretting technique, make it possible to accurately implement any target temperament on the guitar, while retaining full playability.

http://truetemperament.com/index.php?lang=en