Forgot your wallet? You´ll need a better excuse than that for passing on the check. By next year, you´ll be able to pay simply by swiping your cellphone a few inches from a cash register, with a new wireless standard called Near Field Communication. An NFC chip in your phone will send your credit-card number-stored on your phone or on the chip-by way of short-distance radio waves. An electronic reader at the checkout will decode the number and ring up your purchase.