Energy-harvesting component runs wireless nets.
Basically, the idea is you use a patch of piezoelectric fibers, about 4 cm on a side, which generates charge as the fibers get flexed or vibrated, charging a capacitor. When it has enough energy, the charge is used to take a measurement of some kind, and then transmit it to a server. This could be used to, say, keep track of the pressure inside your tires, monitor stress factors at one point in the structure of a building, or report on environmental conditions around one particular tree. With lots of these things, you could make a building that responds actively to earthquakes, or gather data that would allow you to model how the biosphere interacts with climate at a local level (e.g. on the scale of Bay Area microclimates).
Is that cool, or what? :-)