First, thanks to all the people who replied here. There were a lot of good comments. Let me add some quick info:

1) Benghazi Stoves (gasoline-sand burners)
First, it would have helped if I spelled the name right. It's Benghazi (not Bengazi). There is some info on the Web about these stoves or burners, mostly posted by really old British chaps who served in North Africa in WW2. Apparently the good old Benghazi stove was absolutely indispensable back then. For some odd reason, the original Benghazi design does not seem to have caught on here in America. Maybe not too many people live in the desert - that might have something to do with it. Sand is an essential ingredient.

I'll be playing around with Benghazi stove designs over the next couple of weekends. So I'll post back with what I find out. The basic idea is to take a large can, fill it almost to the top with dry sand, and add about 10% gasoline (petrol) by volume. Give the gasoline a few minutes to soak to the bottom of the can, and then light the top of the stove above the sand (by using a long stick and standing well back from the top during ignition). The stove essentially runs on gasoline vapors, which migrate up through the sand and burn at the top surface where the sand reaches the atmosphere. A pretty simple idea really.

Someone mentioned that they had tried the Benghazi burner with kerosene in the Korean war when it was very cold - and it didn't work. This seems quite plausible. If conditions are just too darn cold, then the kerosene vapors would be weak and they might not percolate through the sand much (so you would get weak, ineffective burning).

I'll start by building some small Benghazi's in soda cans, and expand to larger models - once I've got the idea working well.

2) Oil-Water Fires

For some good comments on oil-water fires see the following link:

http://randsco.com/index.php/2007/05/30/p442

This link is basically explaining the physics to home owners ... so they can understand why they shouldn't throw a glass of water on an oil fire in their kitchen. But the basic physics is all the same ... and interesting. I think that Art in Florida got it all completely right. The water vaporizes and atomizes the oil, allowing the oil to flash burn intensely when it mixes with the atmosphere. He's also right on target with the observation that you could use a steady small feedstock of oil to keep this fire going once it's started, and it's pretty interesting that you can actually burn a variety of heavy oils.

I'll put some elbow grease into the oil-water fire techniques in a month or two ... preferably when I can find an abandoned area that has no fire hazards. It's more of a curiousity, really. I could see some survival situations (e.g. aircraft crash, military camp) where an oil-water fire might be quite effective. But since you need another fire just to get the oil-water fire started, it's not an essential survival tool.

all the best,
Pete, California