WSJ writes about near-field communications:
In Japan, NTT DoCoMo offers a mobile-payments service that allows subscribers to make purchases at a convenience store or check into the airport by waving a cellphone. Some subscribers even have their apartments programmed where they can lock and unlock their doors with their handsets.
Mobile commerce is seen as a potential driver of revenue for the cellphone companies, who already are seeing an increase in their revenue from nonvoice services such as text messaging and music and ring-tone downloads. With mobile commerce, carriers could charge a fee for each transaction. The technology would run similar to the small “speed pass” gas cards.