Paying for purchases at the checkout counter by waving your iPhone in front of a payment terminal will soon be a reality, thanks to a new partnership between Visa, Inc. and DeviceFidelity. They have teamed to launch a mobile payment technology for iPhone 3G, iPhone 3GS, and (one would assume) iPhone 4.

According to a press release, the new Apple-certified technology combines a protective iPhone case with a secure memory card that will host Visa’s contactless payment application, Visa payWave.

Introduced in September 2007, payWave allows cardholders to wave their cards in front of terminals in order to pay for purchases at point-of-sale. The technology is similar to MasterCard’s PayPass solution, which rolled out to select markets in 2005. This technology already works at over 32,000 retailers, notes the company’s corporate Web site, and the list is “rapidly growing.”

This mobile payment technology won’t be limited to iPhones. To use Visa’s technology on non-iPhones, users can insert the card into phone memory slots to transform them into mobile payment devices.

Considering that people often lose their mobile phones, the application is designed so that it can be password protected and uses “advanced security technology,” according to the release, to uniquely identify each transaction. If a phone is lost or stolen, the phone’s owner would simply call their provider, who could then immediately deactivate the account, just as they would do if a credit card was lost or stolen.