United Parcel Service, the $36.6 billion Atlanta-based shipping behemoth, has 55,000 sorting workers at 1,700 worldwide facilities. Their Herculean task is to scan -- by hand -- the bar codes on 14.1 million parcels every day so that UPS and its customers know where those parcels are at all times. Beginning in 1996, UPS sorters began using a scanner worn like a ring and linked by a cable to a forearm-mounted terminal, which wirelessly transmitted bar code data to a facility's server.

The devices gave UPS almost-real-time package tracking -- something its customers were beginning to demand. But they also led to millions of dollars in unforeseen outlays. "You can imagine the issues we ran into," says John P. Killeen, director of global network services at UPS. "The cables would get caught on the packages or get yanked out, and once they were disconnected, productivity stopped." UPS needed to buy and store spare wires and other equipment for hundreds of worldwide facilities, and maintenance workers were kept constantly busy fixing scanners.