The mirror, its mount, and the other mechanical components are all made of silicon, putting the projector in a class of device called MEMS (microelectromechanical systems). Sprague says that Microvision developed most of the technology a couple of years ago, but it was waiting for one particular component to become available: a green laser that modulates at the rate required for the projector to work. Only recently have such compact, high-powered lasers become commercially available, he says (see "Ultra-Colorful TV").

Adding a projector to a handheld device, says Ming Wu, professor of electrical engineering at the University of California, Berkeley, could change the way people communicate. Friends might share more movies and pictures, and business professionals who hesitate to pack a bulky projector for a presentation might start using more visuals when they pitch their products, Wu says. "I think it will dramatically change how people will interact with one another," he says. "People won't hesitate to use more image-based communications."

However, some researchers are skeptical that Microvision can pull off a commercially successful microprojector. A prototype is a far cry from a mass-manufactured device that phone makers and consumers will want to buy, says Olav Solgaard, professor of electrical engineering at Stanford. "It's a question of if they can do it reliably and at a reasonable cost," he says. Sprague wouldn't say how much a projector would add to the price of a cell phone.

Microvision expects to release its first products, a stand-alone projector (for media players, cell phones, laptops and other portable devices) and an embedded projector for a smart phone, in 2008. The company has signed a deal with an undisclosed electronics  manufacturer in Asia, but the exact timeline for the products depend on the needs of partners and the energy efficiency of the lasers, Sprague says. In an embedded system, he explains, laser-energy efficiency could be a concern: it's expected that projectors made using existing technology would tap a battery fairly quickly. A phone in "projector" mode would use about 50 percent more power than a phone in "call" mode, Sprague says. But over time, he adds, "it will improve to the point where I do believe people will be watching full-length movies from their cell phones."