In October 2005, Wal-Mart CEO Lee Scott started talking about sustainable development. In September 2006, he agreed with Al Gore and stated that a conflict between the environment and the economy is unnecessary. Now, he's even hired green activist Adam Werbach to shepherd the plan. But there are still plenty of skeptics. Is Scott merely greenwashing -- using sustainability to promote his company's interests -- or has Wal-Mart really become a force for environmental good?