Matt, I don't know about biodegradable water bottles. I'm picturing you carrying around a skin bottle and I'm not sure how well that would go over in today's society. Although I always recycle, I was starting to feel guilty about all the water bottles I used. And since reusing the bottles is supposed to be dangerous (not to mention it makes water taste pretty gross)...I am now using an aluminum/stainless steel bottle from Sigg.