Kim won-jung walked up to a vending machine and bought an orange drink. But rather than insert coins, she paid with the press of a cell phone button.

　　Kim's samsung handset has a debit card inside, and pushing its "hot key" beamed the information to complete the transaction."My brother envies me for all the cool things I do with my phone," said Kim, a math major at the Sook-myung Women's University in Seoul.

　　In one of South Korea's latest efforts to establish itself as a tech-nology trendsetter, the country's three telecom giants, major credit card firms and several banks have been working for a year to enable Koreans to pay for everything from groceries to gasoline by cell phone.

　　"Korea is far ahead in the use of such technology, and it probably leads the world, not just Asia," said Daisuke Okabe, a mobile phone culture specialist at Yokohama National University in Japan,swheresphone payment schemes remain largely in trial mode.

　　If the technology makes sense anywhere, it's here.Almost every teenager and adult has a wireless handset - there are 33.2 million cellular subscribers in the country of 48 million. And unlike the rest of the world - with a few notable exceptions - the cell phone is, in Korea, a lot more than a tool for talking. Kids surf the Internet. Parents transfer money. Some play the lottery, others book movie tickets and millions snap pictures.

　　So why not make the phone a full-fledged wallet?

　　"We are conditioned to think that a credit card is a plastic rectangle," said Cho Eun-sang, a senior manager at Harex Infotech, among the first companies to develop the technology. "But it is actually the data on the strip at the back, and data can be stored anywhere."

　　Instead of handing over credit or debit cards that get swiped, users type their passcode on the phone keypad, point the device at a special receiver on a checkout counter and press a key.The phone shoots the card data in an infrared beam or radio waves. No signature is necessary. For small payments at vending machines, the passcode isn't even required.

　　Transmissions are encrypted and secure, and subscribers who lose their phones can get them disabled within seconds by informing the credit-card company. Phone owners can apply transactions to either credit or debit accounts.

　　An entrepreneur widely credited with spurring mobile payments is Park Kyung-yang of Harex Infotech. He has made millions manu-facturing key chains with embedded radio-frequency chips.

　　Commissioned in 1997 by US oil giant Exxon Mobil Corp to embed key chains with stored-value radio frequency ID chips so they could pay for gas, Park asked himself: Why restrict them to gasoline fill-ups?

　　"I figured a mobile phone was the most logical instrument to place the card in," he said.

　　Harex and South Korea's second-largest mobile phone company, KTF, have also collaborated with Sookmyung Women's University to also let students use their phones as identification cards.The phone's "hot key" can open doors and parking lot gates on campus, register for courses, borrow books at the library or post notices on the campus Website.

　　Getting the payment-by-phone idea off the ground was not easy. It required cooperation from three industries that don't always see eye-to-eye - banking, credit cards and telecommunications.Credit card companies were loath to cooperate so closely with telecoms firms because that would require sharing valuable customer informa-tion and transaction commissions.