A gas station attendant refuels a vehicle with compressed natural gas at one of Cairo’s 14 fueling stations, Nov. 11, 1998. Some 11,000 people in Cairo, almost all taxi drivers, have converted their engines to work with natural gas since January 1996 under a government project. The lure is high savings rather than environmental concern. Natural gas is half the price of gasoline. Industry experts are hailing Egypt’s experience as a valuable lesson for megacities aroundthe world on fighting air pollutioncheaply and safely. (AP Photo/Leila Gorchev)