I had always thought those polycarbonate drinking bottles were cool. You know the ones that are clear, but come in all kinds of neat colors.  But there was always something about them that bugged me when I drank out of them after they had been sitting for a while filled with water -- the water tasted terrible and had a chemical smell to it.  But I just wrote it off to the cost of water portability. 

Now, I know better. Those polycarbonate drinking bottles, along with baby bottles (which we used for years with our children) all contained bisphenol-a, or B.P.A., a chemical which has since been deemed hazardous by a number of authoritative sources.  This article from the New York Times gives a good overview of the situation.

So, what are you to do? I personally have retired all my polycarbonate bottles and replaced them with stainless steel which from all indications offers none of the leaching problems of the bottles containing B.P.A.  Additionally, (in my opinion) the water tastes great.  I still don't think any thing will replace the taste of a cool drink of water out of a glass , but for portability stainless steel is the way to go.