If you need a sturdy yet inexpensive shingle set for a garden shed or chicken coop consider stamping standard aluminium cans into simple shingles using a jig designed by Instructables user robbtoberfest.
You'll probably not want to reshingle your house with these, but they'll work great for garden sheds or chicken coops. The jigs themselves are made from two pieces of wood with square rods installed. Use tin snips to cut the top and bottom from the cans, place the aluminium sheet in the jig and smash it to form shingles that can be attached to your shed with a staple gun.
Make Shignles and Siding Out of aluminium Cans (Beer Can Roof) [Instructables]