Only in Japan: The Best Technologies You Can't Buy

Mobile Wallet Service

Something else that's popular in cell phones these days is the "Osaifu keitai," the mobile wallet service. Phones have smart cards embedded inside, and these cards let you add applications like electronic money, your commuter pass, an airline mileage card, or a credit card just by downloading some software.

The strength of Japan's mobile wallet system is that the industry has settled on a single smart card, Sony's Felica. Once a person's phone has this hardware, he or she can add more functionality with software.

NTT DoCoMo, Japan's largest cellular carrier, gives all its customers an electronic credit card application called DCMX Mini. It has a 10,000-yen ($94) credit limit, and charges appear on the phone bill. Big spenders can apply for more credit and use it just like a regular credit card. All you have to do is bring your phone within an inch of the reader and the transaction can be completed.

Electronic money--something that was tried many times but failed during the dot-com bubble--is now becoming very popular, thanks to "Osaifu keitai."

Of the electronic money systems in Japan, Edy from BitWallet is the market leader, accepted in more than 71,000 convenience stores, bookshops, and coffee chains, and at vending machines. More than 37 million cards and cell phones that support Edy are on the market, and the network handles close to a million transactions per day on average.