IF YOU SPENT any time in a nightclub in Seoul or Pusan last spring, chances are you would have heard a song called “Any Motion” by a pixieish pop star named Lee Hyori.

The song was actually an advertisement for a $600 Samsung cell phone. But it was so popular, it graced the top of the pop charts. The $2 “Any Motion” ring-tone was even downloaded to people’s cell phones more than 3 million times.

South Korea is often described as a laboratory for America’s next high-tech trends. If those trends involve millions of people paying to download a cell-phone ad to their cell phone, it’s not one I’m eager to embrace.

But we may be halfway there. Virtually all of the broadcast networks have announced deals to sell mobile content in the last few months. Yet it’s not clear how to describe all this content: Is it entertainment, advertising or some unclassifiable hybrid of the two?

LET’S SAY YOU actually own a cell phone with the capacity for high-quality video (unlike my Blackberry 7100, which turns catatonic if asked to do anything more challenging than phone calls and email).

You can pay $5.95 for a month’s subscription to Comedy Central, $3.99 for news alerts from “Entertainment Tonight” or 99¢ for a month’s worth of news clips from CBS.

Kids growing up with cell phones demand a huge array of content, Bill Stone, the chief operating officer of a new cell-phone service called AMP’d told me. “They’re addicted to stimulation at all times. The traditional phone companies don’t understand that.”

But for the TV networks, for the moment at least, cell phones are just a particularly intimate form of direct marketing, a way to generate buzz for broadcast channels that create revenue the old-fashioned way — commercial breaks.

As Richard Siklos put it in a recent New York Times column, cell phones hold the same allure for media companies as China does — they represent a vast, untapped market that hasn’t yet translated into a viable business.

LAST MONTH, I sat down with two people who believe they’re building a viable wireless business: Sky Dayton and Stuart Redsun, the CEO and exec VP of marketing of Helio, a mobile service and handset set to launch later this spring.

Helio is a joint venture of SK Telecom, South Korea’s biggest cell phone carrier, and Earthlink, the Internet service provider that Dayton started in the early 1990s from a 600-square-foot Los Feliz office (he was 23 at the time).

SK Telecom and Earthlink are together plowing $440 million into Helio. They’ll also endow Helio with a range of services as yet unavailable Stateside. It’s not clear what these services are, but it’s not hard to imagine the possibilities.

In South Korea, the Economist reported recently, you can walk into a cafe, read the menu on your cell phone, order two cappuccinos, pay electronically and transfer the receipt to your phone bill.

As the marketing director for Vodafone told the Economist, “There is a future, not too far away, when the only thing you will need to leave home with is your mobile phone, because it will be your wallet and your key and all the things it already is.”

For the an emerging generation of cell-phone users, Dayton told me, a mobile device “is not just a phone. It’s a portable life hub.”