An anonymous reader writes "A tiny portable projector, about the size of a pack of cards, may soon replace a ring tone as the most annoying thing on the train or bus. These technical innovations can project an image up to 50 inches in size in dark lighting, making them ideal for on-the-road business presentations. They can also be hooked up to cell phones or media devices, though, possibly introducing a whole new level of social intrusion into US culture. 'Digital projectors were once bulky. These new models, though, are small enough to fit into the pocket of consumers who want a big-screen experience from a small-screen device. Some of the models are expected to be on the market by year-end, or sooner. Prices have yet to be announced. Matthew S. Brennesholtz, an analyst at Insight Media, a marketing research firm in Norwalk, Conn., says he thinks the projectors will initially cost about $350, then quickly drop to less than $300.'"