Still seeking ways to cut the queues, certain supermarkets are piloting a scheme whereby customers walk out without paying. Well, not exactly. Groceries in German store Metro Group in Rheinberg, near Dusseldorf, are tagged with radio frequency identification (RFID) chips market with the price and product information, transmitted to a computer via antenna. Additionally, trolleys have a touch-screen computer, known as a Personal Shopping Assistant, enabling customers to scan their own products. This then permits the store to collect the total shopping bill from customers’ bank accounts. The added bonus for supermarket staff is that they can keep track of quantities of merchandise, thus cutting down on Sundays spent stock-taking  (never much fun, even if it’s a chance to earn some much-needed overtime), and shoplifting - Tesco in the UK recently tagged certain thieves’ favourites to find out whether the scheme worked. It could be years before it is up and running in supermarkets worldwide, although the chip was actually invented 34 years ago.