Teardrops n Tiny Travel Trailers

Neat set up for hot water while camping. I would punch some holes in the bottom edge of the can or even better incorporate it into a rocket stove.

http://marylandwhitetail.websitetoolbox.com/post/D.I.Y.-Backwoods-Waterheater-1647430

With the can set up as is is would be slow heating.
Use a rocket stove and it would be quite good. Could even close the top of the rocket stove and have a small chimney to keep heat in.