It's like real life, only better. "Augmented reality" refers to the layering of information on the screen of a mobile phone, adding semi-transparent objects to the view you can see through the lens of your phone's camera. This might mean directions to the nearest bus stop or a local restaurant review. Thanks to the boom in iPhones, which are equipped with a camera, compass and GPS, travellers can now download a wide range of applications or "apps" that rely on this technology. So, you can think about leaving that guidebook at home.