All around us, there's a technological revolution underway powered by devices as small as a grain of rice. They are sensors, capable of tracking and recording everything we do. They're in our smartphones, our cars, our appliances, even our bodies, and they're connected to the Internet to share information and make our world smarter. Virtually all products that use electricity—from toasters and coffeemakers to jet engines and MRIs—now have the ability to "talk" to each other, and to us. And, what they have to say is profoundly transforming our lives—the way we travel, treat disease and enjoy our homes.