Just as cellular-phone technology untethered talkers from telephone cords, a new wireless standard is freeing computer users from network cables. Wireless Fidelity, a.k.a. Wi-Fi or 802.11b, uses radio transmissions to connect computer devices to a network-or to each other-at distances of up to about 100 meters. With Wi-Fi, you can surf the Web, grab work files from your company's server, and check your e-mail-all without having to plug into a network jack.

The two basic components of a Wi-Fi network are a computer device outfitted with a low-power radio and another radio-equipped gadget known as an access point, which is wired to the Internet or a local network. The two communicate with each other over a free slice of the radio spectrum reserved for consumer use and inhabited by microwave ovens and cordless phones.

The freedom and mobility Wi-Fi offers appeal to a wide range of users. At home, Web surfers can download music on the backyard patio. Businesses and universities can use the technology to avoid the high costs of wiring up offices and dormitory rooms. Police and other emergency-services providers will soon be able to link Wi-Fi with GPS systems to track personnel. The technology is even popping up in public places. For instance, NYCwireless, a community organization, offers free wireless Internet access to all comers in a downtown park. And many retail outlets are seeing Wi-Fi as an inexpensive marketing gimmick. By offering wireless connections for little or no cost, businesses like Starbucks and Borders are demonstrating that liberating people from their digital tethers actually makes them linger longer.