This is the biggest experiment yet in deploying bar-code readers to consumers. Business employees have used them for years to move data (e.g., inventory information) from physical space to cyberspace. But if this experiment works, and I think it will, we will begin scanning codes on our own time.

The magazines will include bar codes on their printed pages, primarily in advertisements. When scanned into a PC, the codes will be the equivalent of a deep Web link, taking the reader directly to a Web page with more information.

The readers can also scan the UPC markings on everything from cereal boxes to compact disks. The software provides links to the product vendors, provided the vendors have paid for the links. (Everybody has to have a business model!)

Other applications abound. At least one mall is piloting a program in which shoppers can build a wish list for an upcoming birthday or holiday by scanning the codes on products they want. But I think the killer app is ordering groceries online simply by scanning empty containers.

One problem is the cost of the readers. A single commercial unit costs more than $100, although the free ones probably cost less than half that in bulk. The main component is the CMOS optical sensor, and the cost of those sensors continues to fall.

The device must be plugged into a PC's keyboard port to scan, which is a major limitation, particularly for some of the applications noted above. The company is experimenting with wireless versions that store scanned codes in flash memory and later upload them to the PC. The modification adds little cost (a few hundred bytes of flash) and greatly increases the units' usability.

Digital:Convergence plans to send out 10 million free bar-code readers this year, and I expect other companies, such as Webvan, to begin similar programs. Although some handheld computers may incorporate this function, the cost of the standalone units has fallen enough that most people won't bother pulling out their Palms.

And soon, you may your own checkout clerk, scanning your groceries at home.

Linley Gwennap is the Founder and Principal Analyst of the Linley Group (www.linleygroup.com), a technology analysis firm in Mountain View, Calif.