Japan's more than 50 millon people or almost half of the cell phone user carry a phone which is capable of doing online transaction. Japan is very advanced in cell phone usage for payment. It developed a new business model for this also. Many people rarely use their wallet for office punch card or for payment with credit card. Their mobile is doing all this. 700 million people are expected to use such capable phone by 2013.
Your mobile will serve as a credit card, home and office key, cash and many kind of ticket and not just for your wrist watch ;)