The World's Greatest Light Bulb

When I drove to the offices of a start-up called Switch Lighting last week, I wasn't expecting much. A company representative had promised to show me something amazing—an alternative light bulb that uses a fraction of the energy of a traditional incandescent bulb and lasts 20 times as long, but that plugs into a standard socket and produces the same warm, yellowish, comforting glow that we're all used to seeing when we flip the switch.