Quit stuffing crumpled bills into your wallet at the cash register. A new wave of (free) digital wallets, like Zong and PayPal Mobile, are quickly replacing paper and plastic. The apps can be used with almost all major phones. Best part? Never worry about change falling out of your pockets again.
Square app for iPhone, iPad, or Android
Store Citi MasterCards and Google Prepaid Cards in your Nexus phone for free and use them by tapping your device on a MasterCard PayPass-enabled card reader. Google is developing collaborations with other providers.
A small plug-in attaches to the headphone jack and works with this free iPhone, iPad, or Android app to accept payments from all major credit cards. The money is deposited in your account by the next day for a 2.75 percent surcharge, making a shopper's life easier.
A partnership between the original e-commerce company and the information-exchange powerhouse Bump created an app that allows you to transfer money between phones with a simple tap. It's free, and it works with iPhone, Android, and BlackBerry.
Download the free app onto any phone; whenever you have to do a transaction, press the Zong button and input your mobile number and a pin, and the credit charges will appear on your wireless-carrier bill.
— Brian X. Chen