A recent article by Jason Johnson presented his vision of how technology could operate in the background, aware of and responsive to context. This idea–context-aware technology–is compelling, and has power to transform entire systems. Many have envisioned better home alarm systems, user-aware car security, more efficient home appliances, and a host of other technologies that quickly identify their human user (or lack of) and respond accordingly. Although the "home of the future" is a dream unrealized, it is not impossible to create. What remains for innovators to solve is how to integrate technology so that it gathers information without disrupting the user. Apple's most recent innovation applies this principle. The iPhone 5S re-introduced an old technology to popular consumer electronics: fingerprint scanners. The 5S scanner hides behind the home button, which users already press frequently. With this feature, the phone becomes "aware" of who is using the device. My eight-year-old laptop has a fingerprint scanner, too, but the iPhone's implementation is slightly and significantly different: using the scanner requires no changes to user habits. This is an innovation not of technical hardware but of designing how humans use.