Light-emitting diodes make for bright and long-lasting light sources, but they’re not used for general illumination because they don’t easily provide bright white light. That may start to change with the 12-watt EnduraLED, a replacement for a 60-watt incandescent bulb. It uses a phosphor film placed a short distance from a high-efficiency array of blue LEDs : the film glows yellow, and the combination yields white light. The LED draws less power than an incandescent and lasts a full 25,000 hours. But the price tag–$60–may leave many people reluctant to change their light bulbs.