Thanks to an energy management program, the lodging company Marriott International shaved off 3 percent of its greenhouse gas emissions per available room in 2008, saving $1.3 million in the process. As a whole, the federal government's Energy Star program estimates that reducing energy use across the lodging industry by 10 percent could save $745 million a year. That's fine for the hotels—and not half bad for the planet. But what can we do as travelers to promote still-more environmentally conscious options? The first step is probably seeking out hotels that go beyond the simple towel/linen reuse policies and incorporate sustainable practices into everything from construction to waste management. Green certifications could use a little clarification, to be sure. But most are at least a good indication that a hotel is trying to do more than just save a dollar or two per room.