When traveling where water is not easily available I certainly do use it to carry a little extra water. It's also become very popular as a substitute for copper plumbing pipe in home construction in my area. Just make sure you do a good job cleaning the interior of the pipe before gluing it together and using a mixture of Baking Soda and water to remove any glue smell/taste after gluing it together.

I detest wearing a backpack on the bike and your right, that’s just me. I know lots of people that wear and prefer a backpack when touring.