It's ridiculously thin and the insides are not bare metal but covered with epoxy. The rigidity of the can comes from its corners and its internal pressure when it is full.
There is such a thing as metal-laminated acrylic but it needs a strong laser so not all laser-cutting shops are able to cut it. If you can find one, however, that would be a more convenient option.
I think a couple of the shops that were once connected to Ponoko offered it a while back.