Smartphone owners are becoming increasingly dependent on their phones to help them shop, according to a recent report from Nielsen. Nearly a third (29%) of smartphone owners use their phones while they shop. What’s more, many want the option to use their phone to pay for their merchandise.

The most popular activity for shoppers using their smartphone is price comparison. Countless apps in the iOS App Store and Android App Market allow users a myriad of ways to check prices of products at both online and brick-and-mortar retailers. Thirty-eight percent of smartphone owners check prices online while they’re in a store, and 38% also shop from their phones. Reading online reviews of products was the second most popular activity at 32%, while nearly a quarter (24%) look for online coupons.

Interestingtly, the least popular activity on Nielsen’s list is also the thing the most smartphone owners wish they could do. Only 9% of users said that they use their phone to pay for goods or services at the point of sale, yet over 70% of all app downloaders said they were at least slightly interested in doing so. Interestingly, iPhone users expressed more interest in mobile payment technology than Android users.

Several Android phones have the necessary near-field communication (NFC) technology to power mobile payment systems. Google even has its own mobile payment service, Google Wallet, that is available to some Android users. The iPhone, on the other hand, has no NFC capabilities, despite persistent rumors that the technology would be coming to the previous two generations of iPhone.

Rumors that the next iPhone would be getting NFC technology gained new life earlier this month when MasterCard executive Ed McLaughlin said in an interview that every handset manufacturer he knew of had NFC technology in the works. When asked if that included Apple, McLaughlin avoided answering directly, but insisted that every manufacturer was working to incorporate NFC.

Whether Apple really is working to incorporate NFC into the iPhone is certainly up for debate, but Nielsen’s numbers suggest that they have good reason to consider it. Almost 40% of iOS users said they were either extremely interested or very interested, while a further 36% said they were somewhat or slightly interested, leaving only 25% of iPhone users who were not interested in the technology at all.

What do you think? Would you like to see mobile payment technology come to the iPhone? Would you like to see it expanded on Android phones? Sound off in the comments.