- 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
- Spare key for your car or front door
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.