This handy resource guide teaches you how to build two dozen contraptions using low-cost or free recycled materials, batteries, and a single motor. Some of the projects include constructing a hovercraft out of a Styrofoam plate, two corks, and binder clips; building a double-paddle wheeler out of paint stirrers, plastic bottles, and a pair of disposable knives; and, turning bamboo skewers, checkers, and a drinking straw into a three-wheeled motorcycle.