NightHiker, thinking about your post and remembering all the historical accounts I've read of people over the centuries mixing wine, etc., with water to make it safe to drink, I wondered if that, too, might not excuse...I mean, justify...bringing a couple of ounces of the good stuff along. I think we could consider it a backup water purification system.

My vote, by the way, would be for Jameson's in the flask.