Mio made some fairly cool heart-rate watches a few years ago but they required you to place a finger on two little pads while running in order to take the measurements. It was interesting, and when you consider that most other heart-rate watches require a chest strap, fairly unique. However, nobody wanted to touch a little thinger just to get their heart rate.Enter the Mio Alpha. This new product uses a precise light sensor to sense your heart rate on the go. No straps, no muss, no fuss. It’s pretty ingenious.