Tesco tests checkout-free shopping

Britain's biggest retailer Tesco is trialing a checkout-free method of payment for its convenience stores, allowing customers to scan products on their mobile devices and then walk out with them, it said on Thursday.The supermarket group is testing the smartphone app at the Tesco Express convenience store located in the campus of its headquarters at Welwyn Garden City, north of London."Using your mobile device you select some products, put them into your basket on your device and then just walk