A "Greener" Water Bottle

When I was in Washington, DC in April at the Engineering Public Policy Symposium, I noticed something different in the Rayburn House Building. No there hadn't been any major renovations or redecorating done since I'd last been there; instead, the typical plast water bottle had been replaced. By what, you ask? By this: http://www.natureworksllc.com/. It's a biopolymer that's compostable. I thought it was uber-cool, and definitely a step in the right direction. It's (obviously) not as eco-friendly as using a non-disposable water bottle such as those made by Nalgene or Sigg, but as you can see here - http://www.greenerdesign.com/news/2008/10/01/corn-based-water-bottles - the House actually composts them instead of sending them to a landfill, which is kind of neat.