You might never need cash in your wallet again. Sure, goods will still cost money -- but the way you pay for them might soon change radically.

Visa (NYSE: V) is the latest company to roll out a digital wallet that will allow users to easily make payments over the Web and via their mobile phones. The near-field communication, or NFC, technology that makes this possible could spell serious opportunity for Foolish investors.

Wallet for the world
Under Visa's new system, customers can pay with one click, using a single username or alias for secure online transactions, or NFC technology over mobile phones.

Besides allowing consumers to control account settings and privacy on their accounts, NFC technology can allow businesses to advertise their products to consumers by sending sales promotion and discount schemes directly to their mobile devices.

Visa is in talks with various banks, card providers, and retailers as it tries to expand this service across the globe. It will be available this fall in the U.S. and Canada, with a worldwide launch planned for next year. While being an early mover here could benefit Visa, the soaring popularity of smartphones leaves plenty of opportunity for other industries to profit as well.

Bountiful beneficiaries
Mobile device manufacturers could make a mint off this movement, selling eager customers a whole new wave of NFC-enabled phones. Models such as Google's Nexus S already have NFC enabled on them. Business solutions provider Intuit (Nasdaq: INTU) has been trying to adapt to the NFC payment method in its GoPayment service as well, allowing users to make payments without the need for credit cards.

Just like the phone makers, carriers could face high demand for the new technology. AT&T (NYSE: T), Verizon (NYSE: VZ), and T-Mobile created the NFC-equipped Isis mobile payment network last year.

Makers of payment terminals could also cash in here. A March report from The Wall Street Journal revealed that point-of-sale terminal maker VeriFone (NYSE: PAY) was joining hands with Google to make terminals that can process payments from NFC-enabled mobile devices.

Banks and credit card companies might also take a slice out of the NFC pie. Another Journal report talks about Google teaming with MasterCard (NYSE: MA) and Citigroup (NYSE: C) to embed Android mobile phones with NFC technology.

This Fool's take
As long as demand for smartphones keeps rising, so will users' interest in applications that let them do new and useful things with those phones. NFC-enabled mobile devices fall in such a category of consumer electronics. A Forrester Research report says that NFC devices are "gaining ground," and related industries are adapting to the technology fast.

But before NFC becomes a regular payment-processing method everywhere, its backers will need to address concerns regarding the security of its transactions. While Visa has put several authentication processes in place, some users still might be leery about using an invisible, all-digital payment system tied to easily lost or stolen mobile phones.

But with Internet commerce constantly expanding, it's only a matter of time before the idea catches on. When it does, related companies like the ones I mentioned here could generate higher revenues from NFC payments. Fellow Fools shouldn't be far behind on the front, either.

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