Kudos to Pointe South Mountain Resort/Scottsdale. Found, on a card atop my bed, during a recent stay: "You're Invited to Help Arizona Conserve Water. ... In an effort to further Arizona's water conservation program, we will be changing your bed linen every third day. ..." (There is, of course, an opt-out option—I wonder how many choose it, thereby making a conscious decision to Waste Away!)
Only 1 in 20 hotels I visit does this.* Too bad ...
(*There's so much "easy stuff" that can be done. Some add towels to sheets on the "Don't Wash" list; a handful put a paper-recycling basket in each room; etc.)