Naturemomsblog has a great review of the BPA-free sippy cup options, and a low-down on why we've determined that our cumulative Bisphenol-A load is something that needs to be reduced.  For me, I'm trying to eliminate my use of plastic for food, and greatly reduce it in other areas.  I don't feel a strong attraction to "BPA-free plastic" - b/c just a year ago they were swearing that BPA was safe.  What else is in there that we're not hearing about yet?  I think I'll just forgo the chemical cocktail for now.  (Here's a guide for choosing the right plastics when it's unavoidable.) 

So we have some Kleen Kanteens, a Sigg, and a Foogo.