I just read some articles that Nalgene bottles are leaching Bisphenol A into your water, which is linked to brain damage (yikes). http://www.radicalcongruency.com/20050405-are-nalgene-bottles-unsafe-1
There are also warning to keep the bottle clean to bacteria doesn't build up, but do not put it in the dishwasher (oops). Since things are still a bit inconclusive with the various reports, I am switching from my trusty Nalgene bottle to stainless steel for the time being, something like Klean Kanteen. Please do a little research before you buy.
Michelle M.'s keywords: Nalgene, reusable, water bottle, plastic