A new book from San Francisco-based SustainLane encourages city planners, economic developers and elected officials to consider the benefits of creating sustainable urban environments. “How Green is Your City?” analyzes the policies, strengths and challenges of the country's 50 largest cities in achieving their “green” goals. The book uses the findings from the 2006 Sustainable Cities Ranking — which measured cities' public transit ridership, urban planning, air and tap water quality, and other factors — as the framework for the book's report cards. For more information, visit www.howgreenisyourcity.com.