I recently purchased a reverse osmosis filter for my kitchen sink, since I realized that it's a lot cheaper in the long run than the Pur faucet mount filter I currently have, and filters it a lot more thorougly.
I wonder how the shelf life of highly filtered, reverse osmosis water compares to tap or bottled water? Since virtually all of the organic matter and minerals are removed(except for carbon, which is added back with a post filter), I'd imagine that there's nothing for the bacteria to feed on and use to reproduce, and therefore I don't know how they could reach a dangerous level. I know that most bottled water is also filtered using reverse osmosis, but I think if you sterilize your container, conditions would actually be more sanitary than at the factory.