Paul Loughridge of Lockwasher Design makes awesome robots, ray guns, and rockets out of vintage cans and other found objects (read: junk).
We've actually featured Paul before on Neatorama a while ago, but this one sculpture, the Sir Lube of Can-O-Lot, is so awesome we just have to post about it. The robot is made from an old hydraulic pump oiler, and comes complete with with a custom made helmet with hinged face guard!
http://www.planetsurfer.net/2008/05/13/top-10-incredible-robot-art-creations/