Months ago, I made and played with one of these: Pepsi Can Stove.

I bought a large can of alcohol at Home Depot, made several versions of the above, got pretty good results, then put it away and forgot about it. Until Charley.

This stove and a small metal cup reheated / cooked chili, oatmeal, ravioli, etc. I was amazed how well it worked. Water boiling for oatmeal in just a few minutes. The first few times I actually cooked with it, I kept cutting back on the amount of fuel since I tended to overestimate how much I'd need.

They're easy to make (in a pinch you can make one with just a knife if you score the can carefully) and cheap. The fuel seems pretty safe and a small bottle would last through a couple of days of meals at least.

Obviously, you can do better with more expensive equipment, but you can't beat this thing for the price / performance.

If you decide to try one, google for "pepsi can stove" or "alcohol stove". There are lots of design variations. The one I posted above isn't exactly the one I have. I can't find the page anymore, but mine doesn't require any tape to seal it. The basic idea is the same for all of them, though.