I just heard Robert Glennon, author of Unquenchable: America's Water Crisis and what to do about it.
He spoke at Changing Hands Bookstore in Tempe. I had already heard him on NPR and saw him on the Daily Show, so I knew the basic pitch, but he had much more time to go into detail, so I'd say it was a worthwhile event. I'd sum up his message as: we need to treat water like a finite and precious resource, through apprpriate pricing and smarter legal and regulatory structures (he's a law professor).
He also reminded me of the link between energy production and water consumption. It takes a tremendous amount of water to produce energy by most traditional means, so when a teacher asked him: "what do I tell my student's when they ask what they can do to conserve water?" - his response was: "turn off a light".
I have a link to his book on my product page.