Google (GOOG) and a number of other companies think that paying for things using smartphones might be the future of brick-and-mortar commerce.

It’s called Near-Field Communication, and it’s a technology found in Google’s Nexus S phone and other smartphones that have recently hit the market. It allows the devices to broadcast a short-range signal that can interact with certain receivers. Users could wave the phone at a payment terminal when they go to check out at the grocery store, and their credit card information would be used instantly to complete the transaction. It could also be used to gather information from movie posters, for example, that would offer advertising information or show times.

But payments are the real power of NFC technology, it seems. According to a report from Fierce Mobile Content, MasterCard (MA) has been surveying customers to see if they’d be willing to use their mobile devices as payment tools for transactions, with 62 percent of those asked responding in the affirmative.

The survey found that 63 percent of respondents between ages 18 and 34 would be willing to make mobile NFC purchases, but that number dropped down to 37 percent for respondents who were 37 or older. MasterCard also found a disparity between men and women in mobile payments, finding that 51 percent of males said they were comfortable with NFC transactions, compared to 40 percent of females.

Respondents in the survey were also asked how they feel about having cell phones on them – 65 percent of 18- to 34-year-olds said they felt more ‘naked’ without their phones than their wallets, compared to 34 percent of respondents older than 35. Between men and women, 50 percent of women said they felt more exposed without a mobile device than a wallet, with only 36 percent of men responding in the affirmative.

MasterCard has worked with Google in the past to help embed NFC payment technology in smartphones, which is supported by Google’s Android 2.3 Gingerbread operating system.  Other companies, like Amazon (AMZN), are considering getting in on near-field technology, considering it the cutting edge of mobile capabilities. Verifone (PAY), a maker of payment terminals for retailers (you’ve probably seen them – they’re often used for scanning credit and debit cards and inputting PINs), is adding NFC capabilities to all its newly manufactured terminals, as well.

But MasterCard’s survey suggests that while 62 percent of respondents are willing to go along with mobile NFC payments, that means almost half of respondents still feel the technology is a bit dubious. There’s a lot of investment going into NFC from many sources, but it’s going to take an investment in convincing people that near-field communication is a trustworthy and safe way of passing financial information before it really takes off.