A simple, low-cost infrared LED speedometer is described that can be fitted to a skateboard, longboard or even a bicycle to measure speed. Notes on building, setting up and calibration are given. When used with a low-cost data logger, continuous measurements of speed can be made while out and about. The device forms an interesting science club project and would be a great introduction for potential physicists and engineers to scientific instrument design, testing and calibration as well as generating lots of their own interesting data to analyse. (Contains 10 figures and 3 footnotes.)