Longstrider said:
There are some great ideas here, but why not go for the more sporting method?
1) Place un-opened can in fire.
2) Everyone stands in a circle around the fire with their plate in their hands.
3) Wait several minutes.
4) What you catch, you get to eat !
I'll get my coat...
Reminds me of a story.
A physicist, chemist and mathematician were shipwrecked on a desert island. Their only rations were in cans, but nobody had a can opener. So they fell to arguing over the best way to open the cans.
The physicist said, "Let's resolve the problem according to the laws of physics. Build a fire and put the can in the fire. The contents will expand, thus causing the can material to fail at its weakest point."
The others didn't like that idea because the food would fly out in an uncontrolled manner and get lost in the sand.
The chemist said, "Let's resolve the problem according to the laws of chemistry. Put the can in salt water. A chemical reaction will cause the metal of the can to corrode, thus weakening it so that we can force it open."
The others didn't like that idea because it would take so long they would die of starvation first.
The mathematician said, "Let's resolve the problem according to the laws of mathematics. Given a can opener . . ."