I know I can buy that stuff, but I was thinking about it from another point of view. I was thinking freebie!!! Besides, I think that a plane skinned with an assortment of different brands of sodas (like a metal patch quilt) would be a one of a kind, or at least I have never seen one.
After I made a couple of tools to work the metal with, I was able to make simple lap joints and made a sheet of metal about a foot long and about 8 or so inches wide in 30 minutes or so. But Twoeagles was right, even the thin cans are pretty heavy. So it would have to be a big plane, with a big motor.
I am going to experiment with forming some aluminum tomorow. I messed with it a little tonight, and made a couple of cones by scribing and breaking the aluminum, like you would sheetmetal. The material had a nice looking industrial look about it. If nothing else, I will make some parts out of old cans when I start my P-51 in a few weeks.