The massive amount of waste generated every day is a hallmark of affluent, modern society. According to the Environmental Protection Agency (EPA), municipal solid waste--a combination of household and commercial refuse--amounts to about 180 million metric tons per year in the United States. That equals almost two-thirds of a ton of garbage for each individual every year. It represents nearly twice as much waste per capita as Europe or Japan, and five to ten times as much as most developing countries. The largest single category is paper and cardboard, which make up roughly 40% of the municipal waste stream. Another major category that constitutes about one quarter of United States garbage is organic materials including food wastes, plastics, and yard and garden wastes. Metal cans and glass bottles represent about 15% of total trash, and the remainder consists of miscellaneous refuse, including building materials, clothing, furniture, electronics, and paint...