We've grown accustomed to seeing cameras on laptop computers, Sharper Image gizmos and Radio Shack toys. Infrared waves surround us, turning on televisions and stereo equipment and transmitting data between our various computing devices. High-tech cars use photonics to notify us when another car is alongside us, when we leave our traffic lane or when there is a baby in front of an air bag. If you didn't already believe that detector technology is ubiquitous, go to J.C. Penney's jewelry counter, where you'll find a wristwatch that snaps digital photos...