Cell phone with onboard video projector

"Mobile phone designers are faced with a paradox," says Siemens user interface researcher Alexander Jarczyk. On one hand, users clamor for smaller, thinner devices. But in the same breath, they scream for bigger screens. With the proliferation of mobile Internet applications, the problem is only going to get worse. Screen real estate is at a premium and designers are hustling to develop new territory, from flexible displays that roll up to zoomable user interfaces. For Jarczyk and his colleagues, though, the world itself is a mobile display. All you need is a projector that fits in your pocket.