Mysterious little black squares are appearing everywhere. From their origins in Japanese car plants to now appearing in advertising, in press articles and magazines, QR codes (Quick Response 2d bar codes) are a brilliant way for smartphone owners to take an interest in a subject further than is possible in the original medium. So you’re sitting on a train, you see an advertisement for a product you want, or a subject you’re interested in? A QR code scanner on your smartphone links you to the source website and before you’ve reached your stop you’ve bought what you wanted or found out what you needed. The creative possibilities are also become clear. Here’s a good example in paint tins. And here’s one we’ve done recently in chocolate drops. Who said they were just little black squares?