I thought this was pretty cool research that FastCompany review in an article.

“Here’s one way you might use it: You’re on your usual early-morning jog. Your mp3 player is set to “shuffle.” A song comes up that you’ve heard one too many times. Instead of having to stop your run, take out your player, and fumble with the buttons or spin wheel to skip to the next song, you just hit your arm about midway up and keep on cruising.”