This concept Coke can design uses a manufacturing process called impact extrusion to form geometric shapes into the can rather than making it round. I'm not sure how practical it is, but I like it. [The Dieline via PSFK]
Instructables has a neat if dangerous tutorial on how to quickly make a key copy by tracing the metal from a Coke can. It's pretty obvious, and with that seed planted in your mind, there's probably no need to read the instructions.