BPA (Bisphenol A) has been in the news recently. In fact, on the Today Show this morning they did a whole segment about it.
I'm sure like me watching that video has made you quickly mentally scan every bottle in your home. I was especially concerned by the baby bottles AND sippy cups AND binkies. I did my own research on this and decided to provide a list of BPA free bottles as well as an article that did a good job of explaining things to me.
I encourage you to read that article as it has recently been updated.
On that note I have to point out that I have older children raised mostly on bottles and I can see no development issues. However, people used to use lead paint in nurseries. I think this is probably the same thing. Just because you can't see the effects right away doesn't mean there aren't any.