Virtually everything that you buy in your local supermarket has a curious little zebra-like pattern the size of a postage stamp printed on it. Barcodes, originally devised about 40 years ago to label ...

QR codes are everywhere these days, from glossy product flyers to billboards to T-shirts. But it’s quite possible you have no idea what a QR code is and wouldn’t recognize one if you saw one. And I ...