An anonymous reader writes: Inventor Jeff Guida has come up with a way to turn any Citibike into an electric scooter. His ShareRoller is about the size of a small briefcase, weighs just seven pounds, and has a 12- to 20-mile range. From the article: '"Years ago, I would've needed a giant engineering company and several million dollars in development research and it still would've taken two years or more," Guida said. But 3D printing has changed all that. In the coming months, Guida hopes to design a universal bracket so that the ShareRoller can be used on any bike. He has some competition there, as there are a few companies that make wheels that convert regular bikes into electric bikes, but he says the ShareRoller is more convenient.'