Since October last year, motorists in Decatur, Ga., have had the option to pay for metered parking using cell phones. After pulling into a parking space near the courthouse, the driver dials in a parking space number and the allotted time before receiving a text message confirming authorization. MobileNOW!, the company spearheading the project, plans to expand coverage later this year to 350 spaces, up from 50.

While fledgling, the initiative could soon spread fast if Americans find it as useful as Europeans: the company's licensor has so far installed 70,000 mobile parking meters in Belgium, plus others in the United Kingdom, Estonia, Slovakia and Ukraine.

"We are trying to use as much existing technology as possible to make it easy for people," says Krista Tassa, president of MobileNOW!, based in Whitestone, N.Y.

Like MobileNOW!'s, many mobile payment schemes have taken hold overseas while remaining in niche pilot stages across the U.S. But with 270 million wireless subscribers nationwide at the end of 2008, representing 87% of the U.S. population, according to CTIA Wireless Association, experts say there's good reason to believe that mobile payments will become as widespread as Internet banking and ATMs (there are others, of course, who have their doubts). If banks aren't ready, other providers, such as wireless phone carriers and payment vendors, will steal the show.

"The one who enrolls is the one who controls," says Richard Crone, chief executive officer of Crone Consulting, a firm in San Carlos, Calif. "This isn't just a first mover advantage, this is a protect strategy."

Crone predicts three phases for mobile commerce in the coming years. The first is underway with mobile self-service, which many mobile banking services offer for account balances and ATM/branch location information. Next will come mobile payments, then user-defined mobile marketing that could prove crucial to attracting merchants. "Financial institutions need to strategically position themselves to ride each of the three waves," he says.

In the United States, paying for goods and services by cell phone still remains in its nascent stages, due in part to lack of simplicity, lack of investment, and cost of hardware. Merchants are reluctant to install any new terminals, which are needed to read new technologies that are already used in cell phones overseas, such as embedded radio chips that enable contactless transactions at the point of sale.

Meanwhile, the payments system in place here already works well: credit and debit cards are accepted almost everywhere, giving a ubiquity and convenience that makes it hard for other payment types to crack the market.

"We have got cash, cards and checks - and they perform adequately for what we need to do," says Nick Holland, a senior analyst at Aite Group. "Fundamentally, whatever you are doing, particularly in the physical payments realm, it has to be better than cash, otherwise it's dead in the water."

Yet with cell phones as ubiquitous as televisions, coupled with the emergence of smart phones, it may be only a matter of time before these devices will match the convenience of existing payment methods, experts say.

Initiatives overseas are proving that consumers like the convenience of using phones to pay bills or make purchases, although the high levels of unbanked in those countries make it a difficult U.S. comparison. In Africa, mobile transfers have taken off across the continent. M-PESA, a payments solution serving the unbanked in Kenya, grew to 1.8 million users in its first 15 months, representing 5 percent of the country's population, according to Aite Group. There, as in the U.S., many cell phone owners don't have bank accounts.