A hybrid Zipcar is shown at a charging station at City Hall in San Francisco, California November 3, 2009. Zipcar has 6,500 cars in 28 North American cities, and offers more than 30 makes of the self-service vehicles by the hour or day to city residents and businesses looking to avoid the high cost of owning a car in the city. To match feature CLIMATE/CITIES REUTERS/Robert Galbraith (UNITED STATES ENVIRONMENT SOCIETY TRANSPORT BUSINESS)