Lots of new information coming out on this. I find it funny that people think tap water is not very healthy when it is monitored several times a day and the bottled stuff from coke and pepsi has lower standards and testing results are kept classified. Unfortunately good bottled water is often shipped from far away places, loosing it's environmental and health benefits by the fuel consumed during travel. High end restaurants in San Fransisco and New York are embracing the low environment impact and are cutting imported water from their menu's.

Here's the article
Top 5 reasons to avoid bottled water

SierraClub fact sheet

So raise your glass high, drink up and refill from the tap.