after following a link from Nalgene Outdoors...
Bisphenol A

"These studies consistently show that the potential migration of BPA into food is extremely low, generally less than 5 parts per billion under conditions typical for uses of polycarbonate products. At this level, a consumer would have to ingest more than 1,300 pounds of food and beverages in contact with polycarbonate every day for an entire lifetime to exceed the safe level of BPA set by the U.S. Environmental Protection Agency."

I think we would be safe drinking from the bottles from time to time.