I love the tip to freeze a half-full water bottle and then fill the other half on the way out the door so you'll have cold water for hours, but is that dangerous, too, as one oft-spread warning suggests?
Mostly, I refill old water bottles again and again. I love the tiny ones that I typically get at blood drives, since in most cases I can put one in a jacket pocket and always have it with me. (In the summer, I go to cons and concerts with cargo shorts. Water bottle in one side pocket, lens in the other.) Am I slowly killing myself?