It seems like everyone has some sort of wearable tech now. I’ve got the Up24, my girlfriend has her Withings device, I even bought a Leapband for a 5 year old girl this Xmas. Usually you either clip them to your belt or wear them around your wrist. Now, there’s one company that’s letting you slip them onto your feet.
The new socks, from Sensoria are actually pretty great (at least in principal). They have sensors in three different spots on the bottom of your feet. As you run, it measures the way you are hitting the ground and the impact you are having with your landing technique. I know several runners who will be lining up for one of these when they become available.