The Rhythm Touch is a small rectangular box the size of half a deck of cards, and it uses electric stimulator pads to ease muscle pain. While the device is meant to help people with chronic pain, the Rhythm Touch representatives pointed out to me that it could be used by people who, say, get aches and sores from sitting and working on the Macs for too long.
To try it out, I had one pad attached to my right shoulder, and another on my right upper back. The Rhythm Touch lets you set the level of intensity from 1 through 5 (5 being the most powerful) and the electrical pulse can simply tap your muscle, massage it, vibrate, or all three. Setting it to massage my shoulder and back at an intensity of 2 for 15 minutes was all I needed to feel decent again.
Rhythm Touch is sold as a stand-alone device or in a package with accessories for $600.