This looks really interesting;

It could be a dieter’s best friend or worst nightmare: technology that knows how much a person has just eaten, knows how many calories he has burned off, offers suggestions for improving resolve and success, and never lets him cheat. And it’s all done by a small, stick-on monitor no bigger than a large Band-Aid.The calorie monitor, which is being developed by biotech incubator PhiloMetron, uses a combination of sensors, electrodes, and accelerometers that–together with a unique algorithm–measure the number of calories eaten, the number of calories burned, and the net gain or loss over a 24-hour period. The patch sends this data via a Bluetooth wireless connection to a dieter’s cell phone, where an application tracks the totals and provides support. “You missed your goal for today, but you can make it up tomorrow by taking a 15-minute walk or having a salad for dinner,” it might suggest. [From Technology Review: When Your Diet Needs a Band-Aid]

At the moment, it’s just calorie counting, but imagine a similar unit that is tracking heart-rate or temperature or any one of a hundred other variables, all being uploaded to some analysis site, perhaps using an accessory on your iPhone?

The next ten years are going to be extremely interesting.