Let's face it. If you've actually paid for somethiing using software and hardware that's built into your phone, you're in the significantly vast minority. That is, at least, assuming you live in the US. But in just a few years, if it's not part of your daily routine you may look as outdated as someone who doesn't have a smartphone today. This trend is going to grow, and it's gonna grow quickly.
Juniper research expects that mobile payments initiated by near field communication (NFC) will skyrocket to $74 billion by 2015. In very much the same way that credit cards eliminated the need to carry around wads of cash, NFC aims to eliminate the need to carry around a credit card. All you need is your phone, which you'll assumedly have with you at all times.
Google Wallet has been the pioneer in this field, but in order to take advantage of that platform you need to be a Sprint customer, own a Samsung Galaxy Nexus phone, and have a Citi credit card (Citibank debit cards don't count) or applicable Google Wallet prepaid card. However, a new platform called Isis - supported by major phone manufacturers as well as the non-Sprint major carriers - is set to launch soon and it could catapult NFC adoption in a big way. From then, analysts expect the trend to grow in a quick and explosive way.