-- Here's a vision of the not-so-distant future:

_Microchips with antennas will be embedded in virtually everything you buy, wear, drive and read, allowing retailers and law enforcement to track consumer items _ and, by extension, consumers _ wherever they go, from a distance.

_A seamless, global network of electronic "sniffers" will scan radio tags in myriad public settings, identifying people and their tastes instantly so that customized ads, "live spam," may be beamed at them.

_In "Smart Homes," sensors built into walls, floors and appliances will inventory possessions, record eating habits, monitor medicine cabinets _ all the while, silently reporting data to marketers eager for a peek into the occupants' private lives.

Science fiction?

In truth, much of the radio frequency identification technology that enables objects and people to be tagged and tracked wirelessly already exists _ and new and potentially intrusive uses of it are being patented, perfected and deployed.