The world continues to urbanize. In the developed world, three quarters of the population already lives in urban areas and as the developing world follows suit 60% of the world’s people will live in urban areas by 2025 (WRI, 1996). Urban areas attract people and businesses by offering greater economic and market opportunities; social, recreational and educational possibilities; and, generally, the promise of a better quality of life. On the other hand, the process of urbanization poses environmental and social problems that are not easily resolved. These include, for example, social segregation, crime, poor sanitation, air pollution, and waste disposal. The great challenge, then, facing cities in the 21st Century rests in realizing cities’ promises of greater economic and social opportunities, while not comprising social equity or the environment.