One of the most important features of a Nalgene bottle is that the lexan is completely nonporous. If you leave, say, cranberry juice in a normal plastic bottle for a fair amount of time, the plastic will absorb the juice, making it sickly red and causing everything thing you drink out of it for the next millenium taste faintly of cranberries. A Nalgene bottle, on the other hand, can be rinsed out with one pass, and will have no more in common with cranberry juice than it did when it was brand spanking new.