Bar codes have revolutionized the tracking of everything from blood samples and groceries to hospital patients. But there remain situations where bar codes just don't cut it. Outdoors weather can make them fade. In dirty factories, optical scanners can have difficulty reading smudged bar codes. And codes printed on paper can be easily tampered with.
An alternative electronic-identification system is available from Videx Inc. in Corvallis, Ore. Its Touch Memory buttons--memory chips encased in tamper-proof steel disks the size of a quarter--can be firmly attached to all sorts of items and store a 56-bit identification number. A quick touch of Videx's TouchWand, a calculator-size device, and you can read a button's information instantly on a liquid-crystal display. The buttons are priced at $7 each; TouchWands go for $747.