"Cash for Clunkers" is a program designed by the U.S. government, under which consumers can turn in cars or light-duty trucks that get less than 18 miles a gallon, in order to promote fuel efficiency. If consumers buy cars that have "window sticker" mileage ratings of at least four miles a gallon more than their old cars, they will receive a voucher worth $3,500. If they buy cars that get at least 10 miles a gallon more than their old car, they receive $4,500. The controversial program concluded Aug. 24, 2009, with rebate applications worth $2.877 billion submitted and nearly 700,000 "clunkers" taken off the road. (Source: NY Times, CARS.gov / Photo: Flickr)