2. San Francisco, Calif.
Declared by Mayor Gavin Newsom to be America's solar energy leader, this vibrant city of cultural tolerance was a 1960s icon and epicenter for the Summer of Love. But in addition to peace, love and solar power, there's also an innovative recycling program with an artist-in-residence at the recycling facility. The artist uses his work to inspire residents to recycle and conserve. San Francisco is also the first U.S. city to ban plastic grocery bags, a concept that supports its effort to divert 75 percent of landfill waste by 2010.