SAN JOSE, Calif.--I'm staring at a table covered in circuitry, a solderless "breadboard," a bunch of wire, an antenna, and some other components--all the things I've been given to build a rudimentary ...

With passive RFID tags, which do not contain batteries, read-range can vary from less than an inch to 20-30 feet, while active (self-powered) tags can have a much longer read range.Drift toward a ...