San Francisco mayor Gavin Newsom has signed legislation that would require all city residents and businesses, restaurants included, to compost food scraps--and to face fines ranging from $100 to $500 if they don’t. Effective this fall, the legislation is the first of its kind in the United States. “Many people thought our targets were overly ambitious,” Newsom said, speaking of the initial proposal. “However, San Francisco is poised to meet these goals. We are currently keeping 72 percent of recyclable material out of our landfill.” Impressive, right? Just wait: the city has plans to divert up to 75 percent of resources from landfills by 2010, and to achieve zero waste by 2020.