It's actually quite a nice piece of
engineering. The walls of the can are very, very thin (as anyone who's
cut themselves on one can attest to) but in the vertical direction the can supports a lot of weight (probably a human, if you step on it
carefully). Of course, in the horizontal direction, it
crumples quite easily, for efficient disposal.
Of course, environmentally it's not quite so nice, but at least they can be
recycled. There have also been talks of
self-refrigirating cans, which would cool themselves off when opened using the expansion of gas released when the can was opened. If I recall correctly, the idea was canned (pun intended) because of the
reduction in the
storage volume of the can.