Not too long ago, the invisible iPhone was nothing more thansatirical fodder for the Onion. Now, Patrick Baudisch and his team of researchers at the Hasso-Plattner Institute have moved closer to making it a reality, with a new interface that can essentially transfer an iPhone touchscreen to the palm of your hand. The device involves an Xbox-like depth camera, mounted on a tripod, that can register the movements of a person's finger across his or her palm. Special software then determines the actions these gestures would execute on a user's iPhone, before transmitting the commands to a physical phone, via WiFi radio. Unlike MIT's motion-based "sixth sense" interface, Baudisch's imaginary phone doesn't require users to learn a new dictionary of gestures, but relies solely on the muscle memory that so many smartphone users have developed. During their research, Baudisch and his colleagues found that iPhone owners could accurately determine the position of two-thirds of their apps on their palms, without even looking at their device. At the moment, the prototype still involves plenty of bulky equipment, but Baudisch hopes to eventually incorporate a smaller camera that users could wear more comfortably -- allowing them to answer their imaginary phones while doing the dishes and to spend hours chatting with their imaginary friends. Head past the break to see the prototype in action.