London-based Intelligent Energy developed the Emissions Neutral Vehicle, or ENV (pictured), which Autoblog reported in March last year. Jerry Garrett of the Copley News Service reports riding the prototype. He found the noise, or lack of, from the ENV's motor most disconcerting. Otherwise, he found the bike responsive and easy to maneuver, and had no difficulty slaloming test cones.
[Sources: Treehugger; Copley News Service via Boston Globe]