Submitted by Doug
ED -- This slick little piece of kit was mentioned in the comments of the write up I did on the Nalgene bottle and I though it worthy of its own entry. Thanks Doug! Keep posting!
They do make a metal cup that nests with nalgene bottles. Go to Eastern Mountain Sports or REI's websites and search for "NESTER'S Space Saver Cup". I got mine for around $7. I rigged insulated carriers on my camping backpack's hip belt and it works great!