Tanita scales are so cool. But this Tanita Innerscan BC-545 measures a whole lot more than your weight, so much so that the company calls it a Segmental Body Composition Monitor. It can give you readings of how much fat is in each arm, each leg, and of course, that potentially ample repository of adipose tissue (that's blubber in doctor talk), the trunk area.
Stand on the four sensor plates and pull up on two retractable electronics, and the device sends a weak electric current through your body to see what you're really made of. It keeps track of your measurements and can display your progress in days, weeks, or months over a three-year period. One thing that will be much lighter right away is your wallet—the BC-545 costs $390.