Numerous websites agree that the following US cities make for smart, green urban centers. They do more than recycle: They’ve developed ways to add green to the urban clutter; decrease waste and energy consumption; develop innovative, alternative methods of transportation... and those are just some of the high points. There simply isn’t enough space to discuss all of the sustainable success these top 10 cities have enjoyed -- from rooftop gardens on city buildings to bike-shares, car-shares and bold goals like converting the city’s taxi fleet into earth-friendly rides.