Check your credit cards for an RFID logo, usually consisting of a few wavy lines. It allows you to wave the card over a special reader to make a purchase, thereby saving you the effort of swiping it through one of those old-fashioned readers. They are becoming common, especially through card renewals. To protect you against thieves who can access the radio waves and steal your identity, get a secure card holder from various local stores.–John Hallgren