Japan and South Korea are still way ahead of the U.S. when it comes to turning cell phones into mobile payment devices. But the concept could finally be gaining some steam, especially after Starbucks on Wednesday unveiled a new iPhone app that allows people to pay for their coffee drinks with their iPhones.

Now, a Seattle startup called Billing Revolution -- led by former WeddingChannel.com founder and former AT&T Wireless executive Andy Kleitsch -- is looking to take the idea even further. Billing Revolution today announced a partnership with Authorize.net to help merchants who use the payment gateway conduct mobile transactions.

The mobile credit card payment system allows more than 200,000 Authorize.net merchants to sell everything from pizza to magazine subscriptions to hotel rooms, said Kleitsch.

Kleitsch said that the Starbucks mobile payment app is a good example of how retailers are thinking about mobile shopping, turning mobile users into buyers.

"As more merchants look to mobile as a retail channel they will need a mobile checkout that seamlessly integrates with their current transaction platform," he said. "The Billing Revolution service sits on top of the merchant's current payment gateway and processor -- enabling merchants to quickly and easily process mobile transactions without any development or surgery to their current payment systems."

We've seen some other activity in the mobile payments arena in the past 12 months, including Innerfence's Credit Card Terminal application for the iPhone.

Kleitsch said his company's system is different. Innerfence puts the credit card processing power in the hands of merchants, while Billing Revolution turns that over to the consumer.

"The merchant is not typing in the credit card data, the customer is," he said.

There's still a long way to go before this technology will catch on with mainstream U.S. consumers, may of whom are just getting accustomed to text messaging.

But Billing Revolution has a powerful ally in its corner as it looks to attack the market.

The company is backed by none other than SK Telecom Ventures, the venture arm of South Korea mobile powerhouse SK Telecom. SK Telecom has been a leader in mobile payments in South Korea for years.