Cash, credit or debit? You may one day have far more choices to make at the checkout counter. A group of big retailers, including 7-Eleven, Best Buy, CVS and Wal-Mart, said on Wednesday that they were forming a company that would offer a way for customers to pay for purchases with their smartphones, joining a wide array of groups and companies seeking a piece of this market. Other than announcing the formation of the payments network, to be called Merchant Customer Exchange, the companies released few details about how their mobile payments would work, and did not say when the technology would become available. Read the full story at The New York Times.