I can immediately tell if I'm drinking tap water. I don't much like bottled water most of the time either - it's over priced and I hate dealing with the recycling. I find it amusing that dasani / aquafina cost more than the equivalent amount of coke or pepsi... so they sell you the filtered water without the cola syrup and it's more. Go figure. Personally, I have a reverse osmosis filter at home that delivers awesome tasting water.