It was just a few weeks ago that I posted on Shay Shafranek’s digital ruler. At the time, though, I over looked one of his less practical inventions, but unlike the ruler concept the Speed Bat is a working prototype. The device, which is designed to power a person in a pair of inline skates, appears to be a modded weed wacker. It’s actually a rather ingenious idea since it is relatively practical for those living and a working in city and don’t have the storage for a bicycle. Hit the below video for a complete demonstration complimented by a mashup that must violate YouTube’s copyright rules.