Cellphone vs. leather wallet: How long before it happens?

I have long believed that the cellphone will eventually replace the what I describe as the "leather wallet."  I mean, think of everything you carry in your wallet that could someday be handled, in some way by your cellphone.

• Photos of family and loved ones (bet your wallet doesn't include videos!)
• Identification such as driver's license, gym membership, library, warehouse club
• Loyalty cards to get a discount at supermarkets and other stores
• Phone numbers, notes and other things of value you've written on slips of paper
• Business cards
• Payment cards including debit and credit cards
• Cash
• Spare key for your car or front door

These are all functions that can be (or are already being) accomplished using the electronics in cellphones.

Mobile operators and cellphone vendors in Japan have done a great job in building the complete ecosystem to accept payments and identification using Near Field Communication (NFC), a technology that will have a hard time gaining a foothold in the US. Why? Because, in Japan, everybody cooperated to get it launched.  All three of the big mobile operators made a decision to support the same technology and support the ecosystem (one mobile operator, DoCoMo, invested millions in a chain of convenience stores in order to install NFC readers at cash registers).

In the US, mobile payments are important but will have to take a much different path. Some day, though, we could see most of the functions of a leather wallet being handled by our cellphones. It's going to be slow, there will probably be several dead ends, but, I believe, the interest is there, and the technology is available. It's just a matter of building up to the critical mass required.