Networks of wireless humidity sensors monitor fire danger in remote forests. Nitrate sensors detect agricultural runoff in rivers, streams and wells, while distributed seismic monitors provide an early warning system for earthquakes. Meanwhile built-in stress sensors report on the structural integrity of bridges, buildings and roadways, and other man-made structures.

On the factory floor, networked vibration sensors warn that a bearing is beginning to fail. Mechanics schedule overnight maintenance, preventing an expensive unplanned shutdown. Inside a refrigerated grocery truck, temperature and humidity sensors monitor individual containers, reducing spoilage in fragile fish or produce.

Sensors embedded in clothing, networked with additional in-body sensors, continuously monitor our vital signs. The first indication of an impending heart attack or dangerously high blood pressure leads to early medical intervention. Surges in a diabetic's blood sugar levels, monitored continuously by minuscule sensors, trigger insulin delivery from an infusion pump, perfectly mimicking a healthy pancreas.

Firefighters scatter wireless sensors throughout a burning building to map hot spots and flare-ups. Simultaneously, the sensors provide an emergency communications network. Miniature chemical and biological sensors in hospitals, post offices, and transportation centers raise an alarm at the first sign of anthrax, smallpox, ricin, or other terror agents.