Reuters: There's an old joke about the number of people it takes to change a light bulb. But because the newer energy-efficient kinds contain tiny amounts of mercury, the hard part is getting rid of them when they burn out. Mercury is poisonous, but it's also a necessary part of most compact fluorescent bulbs, the kind that environmentalists and some governments are pushing as a way to cut energy use. With an estimated 150 million CFLs sold in the United States in 2006 and with .. Link http://www.enn.com/today.html?id=12475