We've been reading for the last few years about the onset of Radio Frequency Identification tags (RFID). RFIDs are very small chips, about the size of a grain of rice, that transmit information to a receiver. On the plus side, RFIDs are being used more and more for inventory purposes-ie, putting RFIDS into or on merchandise and, because the item transmits information about itself, an inventory tracker can more quickly and presumably more accurately track what's on hand (WalMart was one of the first to use it).

RFID technology already is in use in the supply chain to track assets like containers and trailers. This type of use typically involves a battery-powered transponder attached permanently to the asset. When the transponder passes stationary readers, installed at places like the entrance to port terminals or truck yards, the event is captured and sent to a computer server.

For cases and pallets, a much smaller and less expensive tag is required. Such tags have been developed and currently are being tested in a variety of proof-of-concept projects. They typically consist of very small RFID microchips and antennas that can be embedded in a cardboard carton or layered on a printed label. These tags do not have their own power source, but when they pass within range of a reader