Scores of companies are betting that delivering audio content of all kinds to handsets could be bigger than camera phones and ringtones.

A small deception is being practiced in Los Angeles and Washington, D.C. In those cities, 300 people who might look like typical headphone-wearing commuters are listening to the radio while stuck in traffic or holding on as their overcrowded train chugs along in the morning rush hour. But they carry a secret.

They aren’t listening to music on their portable radios, nor playing podcasts of homebrewed radio programs on their iPods. They’re grooving to the radio, all right, but it’s flowing from an unexpected source: their cell phones.

This small army of testers is checking out Motorola’s iRadio service, expected to launch by yearend. And these listeners won’t be on their lonesome for long. Scores of handset makers, wireless carriers, Web portals, and even satellite radio companies are starting up services that offer radio over cell phones — betting that the market for such services could be as big as camera phones and ringtones.

“VERY INTUITIVE.” Chances are radio services will be a hit with the 2 billion wireless subscribers worldwide. “Mobile phones are always with you,” explains Nancy Beaton, a general manager at telco Sprint, which became the first carrier with a commercial cell-phone radio service in December. “Because customers are familiar with how the phone works, adding radio can be very intuitive,” says Beaton.

And many users want that addition. According to surveys conducted by America Online, a unit of Time Warner, more than half the respondents say they would listen to the radio on their phones. AOL is in talks with wireless service providers to offer its online radio stations on mobile phones within months.

Cell-phone radio might have greater appeal than mobile video. Handset maker Nokia is currently testing cell-phone video over a new network, but it has discovered that many consumers end up using the video broadcasts as radio. They listen to them most of the time, instead of squinting at the phones’ two-inch screens, says Kari Lehtinen, a manager at Nokia. “Radio seems to be surprisingly popular,” he says. So, Nokia expects the new network, when launched sometime in 2006, to also offer numerous audio channels.

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