When choosing a vendor or hotel property one of the first questions to ask is about their environmental policies or mission statement. It is a quick way to tell how inherent environmental responsibility is to an organization. It will also give you a quick read into the depth of their commitment. There is an excellent post on Environmental Leader by Matt Courtland of The Natural Strategy highlighting some of the major hotel chain's mission statements http://www.environmentalleader.com/2010/03/19/saunders-hotel-group-takes-initiative-in-energy-efficiency/
The comments are also worth taking a look at and you might want to join me and add your own two cents as well.