For those who've always had the slightly obsessive-compulsive urge to know exactly how many calories you burn in a day (including all the downtime spent snoozing or on more sedentary activities), the Accelerometer may just be the device for you. Small and light enough to clip to your belt or waist, this device is designed so that you can have it on you all day without even realizing that it's there. It relies on a precision motion sensor, "similar to the technology that NASA uses to monitor the movements of astronauts in space." If that isn't precise enough for you, I'm not sure what is.

All you have to do is punch in your weight and the device does the rest, calculating how the day's physical activity works out in terms of calories. There's also a 9-day memory capacity so that you can keep tabs on your progress. Handy for athletes, no doubt, and also for the rest of us who just want to know how much (or how little) we've accomplished for the day.

Available from Hammacher Schlemmer for $49.95. Via Uber-Review.