Google wants to replace your wallet. "Our goal is to make it possible for you to add all of your payment cards to Google Wallet, so you can say goodbye to even the biggest traditional wallets," explains Osama Bedier, Vice President of Payments in a post announcing the official release of Google Wallet yesterday. Google's Android software has already replaced your phone, your discman, your phonebook, and now it's ready to lighten your load. At least that's how two Google developers explain it in the company's accompanying video. But unlike releasing a phone, replacing a credit card with a phone will take a lot more than a slick application. 

No matter how well the application works--and the reviews for Google Wallet are pretty good--Google will face lots of roadblocks before the technology can become mainstream enough to full-on replace your wallet. 

There aren't enough credit card companies on board. Google wallet only supports one credit card: the Citi Mastercard. "I don’t have one of those, and had a hard time finding anyone who does," explains TechCrunch's Greg Kumparak. As a crutch, Google also provides a prepaid card, which can be loaded up with cash. But it doesn't exactly work like a credit card, and would most likely supplement, not replace your other cards. Google claims it has other partnerships in the works, "though there’s no clear ETA on when they’ll be ready for customer use," reports Wired's Mike Isaac.

Not all retailers have the infrastructure to support it. Google Wallet only works with a compatible card reader. "Therein lays one of Google’s biggest challenges: getting these card readers everywhere," continues Kumparak. "Even out in the relatively low-tech East Bay of California, I had no trouble finding locations to at least test things out." If you can't use it everywhere, you can't totally forgo your wallet. 

It has very bad battery life for a wallet. Your credit cards and cash never run out of battery life. A phone does. "If your phone runs out of juice, consider it the end to your cash flow. Short of finding a nearby extension cord or a back-up $20 in your sock, you won’t be able to pay for much of anything," continues Isaac. Imagine getting stranded sans outlet: No phone, no cash, no nothing. 

People just aren't used to using phones as credit cards. It might be easier or faster or provide cool coupon deals, as we've reported, but people don't like to change habits. "Every time I use Google Wallet, the person on the other side of the register looks at me like I’m Marty McFly and I’ve just stepped out of the DeLorean, hoverboard in hand."