AT&T Wireless on Tuesday launched a wireless data service that delivers E-mail, instant messaging, calendars, contact lists, and other information to users as text or still-color images displayed on screen-equipped digital cell phones.

The mMode service is available now in cities where AT&T Wireless has upgraded its network to Global System for Mobile Communications/General Packet Radio Service technology. So far, upgraded cities include Detroit; Indianapolis; Kansas City, Mo.; Las Vegas; Miami; Fort Lauderdale, Orlando, Tampa, St. Petersburg, and West Palm Beach, Fla.; Phoenix; Portland, Ore.; and Seattle. AT&T Wireless will expand the service to San Diego before the end of April and will add other cities during the rest of the year.

AT&T Wireless will sell three mMode service plans, according to expected usage. Charges for mMode will be in addition to a user's regular cell-phone charges. The first plan, Mini, is $2.99 a month plus 2 cents for every kilobyte of data transmitted. The second, Mega, is $7.99 a month, which covers 1 Mbyte of transmitted data, with additional kilobytes billed at 1 cent each. The third plan, Max, is $12.49 a month and includes 2 Mbytes of data, with additional kilobytes costing 1 cent each.

In addition to signing up for an mMode service plan, customers must buy a GSM/GPRS-compatible phone and sign up for a GSM voice-calling plan. Right now, phones available for use with mMode include the $200 Sony Ericsson T68, the $200 Nokia 8390, and the $80 Motorola Timeport P7382I.

With mMode, users can synchronize their cell phones with their desktop E-mail, contacts, and calendars, including Microsoft Exchange and Lotus Notes, as well as all other major messaging and personal-information-management products, a feature that might be useful to busy execs, although the service is primarily intended for consumers.

Despite a questionable demand for wireless data services in the United States, AT&T Wireless decided to launch mMode because "the service is compelling, the network is there, and there's no reason from our perspective to wait," says Andy Willett, VP of data services at AT&T Wireless.

Before launching it, however, AT&T Wireless studied the successful iMode service offered by wireless carrier NTT DoCoMo in Japan and adopted parts of its approach, Willett says. "Specifically, the way in which we work with third-party content providers is very consistent with what DoCoMo taught us about iMode," he says.

The service launch is a positive development for the wireless data market in general, even if adoption rates are uneven, says Ronnie Galang, associate consultant at TeleChoice. "The service will probably get mixed reviews, just as third-generation services are getting mixed reviews outside of the United States," Galang says.

And, because the service is designed mainly for consumer use, it ignores the sector that's most likely to adopt wireless data services first, Galang says, since business customers have greater need for mobile data and a greater ability than casual users to pay for the capability.