Bottled water is, as Felix Salmon writes, ridiculous. But if you live in an country where you can’t trust the state to tell you the truth about the quality of the piped water, and where there are strong bottled water brands, you are probably better off drinking bottled water. After all, strong, trusted brands are worth a lot, so the owners have a lot to loose if they don’t practice strict quality control.
In the US, it makes no sense to drink bottled water. In China, it makes no difference, you can’t trust either. But traditionally in Italy and France, drinking bottled water made sense.