That's according to a new report released by research and advisory firm Aite Group titled, "Sizing Person-to-Person Payments in the United States, United Kingdom and Australia." The report, which was based on an August 2010 survey of more than 3,000 consumers in those three nations, reveals consumers' P2P payment behavior by method, channel and recipient.

While consumers can take their pick from many payment methods, cash is used the most in P2P transactions. Aite Group found that in the past year, 84% of U.S. consumers (as well as 90% of Australian consumers and 89% of U.K. consumers) used cash in a P2P transaction. The survey found 51% of the total number of P2P transactions in the U.S. (as well as 52% in Australia and 65% in the U.K.) were made using cash.

"Despite the emergence of many alternative methods of payment, cash still accounts for the majority of P2P payments in the three regions studied," Aite Group's Ron Shevlin said.

Check usage is significantly higher in the U.S. than in the U.K. and Australia, with 58% of U.S. consumers using checks as a P2P payment method, compared to 40% of consumers from the U.K. and just 18% from Australia. But Aite Group researchers say this U.S. percentage could soon decline.

"Australia and the U.K. have each taken formal steps to enable and encourage the online transfer of funds in order to replace checks," Shevlin said. "Aite Group believes that the United States will take similar actions in the next few years."

Out of the many channels through which P2P transactions can be completed in the U.S., most were made in person, Shevlin said. Face-to-face transactions account for 73% of this past year's P2P transaction volume and 66% of P2P dollar volume.

While very few Americans use mobile devices to make P2P transactions (Aite Group finds households spend an average of just $8 per year on P2P transactions made using the mobile channel), researchers expect that amount to increase. According to the report, Nielsen estimates 50% of Americans will use smartphones by the end of 2011, causing mobile payment methods to start pushing cash and checks aside.

"The tiny percentage of P2P transactions that are conducted through a mobile device belies the future potential for mobile P2P payments," Shevlin said.

Aite Group also foresees that payment providers will take note of the most popular P2P scenarios and develop use-case-specific applications. For example, they may offer a payment application that allows customers to split a restaurant bill-an activity practiced more than 1.2 billion times this past year in the U.S.

"Payment providers will develop and market applications specific to use cases in order to motivate payment behavior change," Shevlin said.

The report also covers how much consumers spend annually on P2P payments by household. In the U.S., the average is $7,500, or 96 transactions; in Australia, it's AU$ 14,000, or 120 transactions; and U.K. households spend an average of 2,500 pounds, or 50 transactions.

Aite Group also looked at the most popular types of P2P payments and the relationships between consumers and recipients.

The top five P2P payment types are similar in the three regions studied. In the U.S., most P2P payments are made as birthday presents, as Christmas presents, to split a restaurant bill, to offer a tip and to give to charity. In both the U.K. and Australia, the top five P2P payment types are for birthday presents, Christmas presents, splitting a restaurant bill, fundraising and charity.

Aite Group found in the U.S., most P2P payments were made between family members, with that type of recipient accounting for 32% of this past year's transaction volume and 47% of dollar volume.

Similar results were found in Australia and the U.K., with family member recipients accounting for 27% of transaction volume and 30% of dollar volume in Australia; in the U.K., the numbers were slightly higher, with family members accounting for 29% of transaction volume and 33% of pound volume.