It may not have had the impact of indoor plumbing, but the Universal Product Code certainly has changed the way the world views the photonics industry. Thanks to the little black bars on everything from apples to zippered bags, lasers -- once the stuff of science fiction -- now find themselves in all segments of our lives, including the goods we buy, the books we borrow and the mail we receive. Those little black lines, commonly referred to as a bar code, were developed in 1973 by George Laurer, then of IBM. His code has changed very little since that year, when the product identification method was beta-tested on a beanbag ashtray thrown at high speed past a white-light scanning system. Apparently the test worked. As bar-code use exploded throughout industry from grocery stores to hospital patients, low-power lasers and polygon scanners quickly usurped the inefficiency of white-light sources, according to Ben Nelson, a historian who recently published "Punchcards and Barcodes" (Helmers Publishing, $39.95). The code's widespread acceptance may soon prompt the US to add another line, raising the number of store codes from 99,999 to 999,999. European and Asian markets already have added the "sixth number," Nelson said. To businesses, the code provides all kinds of valuable information, such as buying patterns, where products are most visible, what kinds of products are purchased together, inventory control and other market data. It keeps a company in touch with its patrons. Alphabet soup Although the Universal Product Code certainly has become "universally" accepted, it hasn't stopped researchers from trying to develop new ones. Since the 1970s, Nelson has collected 292 versions of the bar code. Some depended on color, he said, while a unique code used the lines that form the bottom of characters in the alphabet. Of course, not everyone is happy about the insidious acceptance of the bar code. Even though it provides all kinds of useful data to a computer, it can mystify some patrons, who search in vain for a good ol' alphanumeric price tag. Maybe photonics needs to come up with a pocket scanner with infrared data transmission for quick reference. There's always room for one more gadget on a person's keyring.