In the future according to Google, no one will leave their homes with anything more than a cell phone. The goal is to use Google Wallet to literally digitize everything from your credit cards to your driver’s license to your house key.
Is it possible? Unquestionably – especially when you think about how far cell phones have come in the past. Since the initial debut of the iPhone in 2007, app developers have been working to build more and more uses for the cell phone, and they’ve already replaced much of what we thought important once.
After all, when was the last time you used a GPS in your car? When was the last time you picked up a newspaper to read the headlines? Set your alarm clock? All of them have been replaced by the cell phone, and the idea of turning into your wallet can’t be far behind. In countries like South Korea and Japan, it’s already happened.
Source: http://www.cnn.com/2011/10/09/tech/mobile/google-mobile-wallet/index.html


