This is a heavy piece of kit, but I thought it was interesting nonetheless
http://www.biolitestove.com/campstove/camp-overview/features/
Has anyone used one of these? Can't help but think this could be developed further with a water jacket around the fuel to boil water instead of the perforated heat shield. If a few hundred grams could be shaved off it with Titanium it might even be a practical piece of equipment one day.