BARCELONA, Spain (AP) — Many people use their smartphones to watch video, play games and wake them up in the morning. Some even use them to generate digital boarding passes to fly. So why not use phones to buy stuff at retail stores as well?

A variety of mobile wallet systems store credit or debit card information on phones in encrypted form, offering more security than standard plastic cards with magnetic stripes. To make a purchase, simply tap the phone on a card reader or wave a bar code over a scanner. There’s convenience in not having to fish out your card.