Contactless payment methods are slated to become the norm by 2020, according to a recent report from the Pew Internet & American Life Project that polled a panel of technology experts.

Approximately two-thirds of respondents (65 percent) believe most people will have fully adopted the mobile wallet as their primary point-of-sale payment solution in eight years, usurping cash and credit cards as the gold standard. The change will come as more consumers rely on personal hardware and software for transactions, making smartphones the ideal conduit in that sense.

However, there will still be a place for cash and credit cards in the future. As many as 33 percent of the polled experts believe consumers will not trust the safety and privacy of near field communications (NFC) technology for financial transactions. Consumers, they say, will be hesitant to use their phones for big transactions and thus don't think mobile payments will gain a lot of traction by then.

Factors barring the adoption of mobile payments

Indeed, these privacy fears are a big reason why adoption of mobile technology has been slow thus far. Additionally, the tech experts noted the desire for anonymous payments, a lack of infrastructure to support widespread mobile payment adoption and resistance from companies already entrenched in the existing payment systems.

"As much as I'd like to see a money-free world, I'm afraid the opportunities for the hackers and pirates are too great," one respondent told Mashable. "I'm happy to buy my $2 Starbucks using my Android but I don't know that we will ever feel secure enough to make much larger purchases that way."

Supporters of mobile payments, however, were quick to point out how many countries throughout the world are already using similar systems.

"The 2020 date might be a bit optimistic, but I'm sure that this will happen," study participant Hal Varian, chief economist at Google, explained to the news source. "What is in your wallet now? Identification, payment and personal items. All this will easily fit in your mobile device and will inevitably do so."

As the number of smartphone owners continues to grow, so too does the reality of a mobile payment future. According to the latest data from comScore, upward of 100 million Americans own smartphones such as the iPhone or HTC Evo. To put that in perspective, that's approximately half of the United States' total mobile subscriber base.