I’ve had the pleasure of working with the volunteers at Chicago’s Working Bikes Cooperative (WBC), an organization that collects cast-off bikes and repairs or refashions them for use in the city or in far-off countries. They also make bike machines, such as pedal generators and water pumps, for education, fun, and practical use. (And they’re featured in The Human-Powered Home.) WBC recently posted instructions for making devices they debuted at the Midwest Renewable Energy Fair this summer. Another WBC page lists instructions and videos for making a wide variety of pedal-powered devices.