Strobopick: The Super Miniature Guitar Tuner
If you love playing guitars, the StroboPick Guitar Tuner is a pretty cool gadget to have. Shaped like a guitar pick, this amazingly small guitar tuner works with strobing LEDs.
"By shining a flashing light at a vibrating string you can clearly see whether the string is in tune with the light source. StroboPick emits 6 light frequencies matching standard guitar tuning with great precision."