Imagine what the world would be like if we could re-purpose — or double-purpose — all the old structures we’ve got lying around. WindPole does just that, by outfitting old radio towers with sensors to track the speed and frequency of gusts of wind. Since these towers are already built, why not use them for another purpose other than shuttling radio waves and cell phone calls? The cost of installing a sensor on an old tower is about half the cost of constructing a whole new structure, and since the towers are pre-existing, no permits are required. So far Windpole‘s coverage includes over 7,000 towers spread over 39 states.