This instructable walks through the process of making a mouth-friendly edge on an aluminum bottle turning it into a Cool Reusable Metal Tumbler Cup.
The steps outlined here are, stand-alone, instructions to make a complete Metal Tumber from an aluminum bottle; suitable to use as a lightweight tankard for all your favorite beverages.
(I recommend the chilled kind. Remember science?...aluminum is an excellent heat conductor; you don't want hot cocoa burns on your fingertips as well as the tip of your tongue!)
However... those of you familiar with the Aluminum Bottle Backpacking Stove,
( http://www.instructables.com/id/Aluminum-Bottle-Alcohol-Stove/ ) will also recognize the technique demonstrated here, as a means for creating light weight cooking tools to accompany an alcohol stove.
The video below shows these Aluminum Bottles & Tumblers in use as a lightweight backpacking cook / storage system.