Fitness and activity trackers come in many shapes and sizes. Some you wear on your wrist; others you stick in your ears; and some you clip onto your belt. Emotia's prototype activity tracker actually is a belt; or more specifically, a belt buckle called Belty. As you'd expect, it measures steps like every other tracker, and connects to your phone via Bluetooth to feed this data into an app, which acts as a virtual fitness coach. You can also set it to vibrate when you've been sedentary for too long and, more importantly, it can keep tabs on your changing waist measurement, which can be a good indicator of your risk of developing weight-related conditions. What I've described so far is all well and good, but forget that, because this belt buckle is also motorized, and capable of tightening and loosening itself to keep you as comfortable as possible at all times.