Backpacker magazine, a very decent American walking mag, has run various articles and competitions with regard to ultralight stoves, usually alcohol burners, made by the readers. Coke cans figure heavily in the designs.
www.backpacker.com probably has some of the details, as they archive a lot of their material.
For a wood-burning stove I tend to carry a folding model I bought from Cabela's, which packs up to the size of a paperback novel but is a bit heavy. It's a clever design, probably too complex for its own good though, but I can't say that it has a clear advantage over using a big coffee can. It does lift the fire off the ground, though, which aids in the ventilation.
Another American stove I'd love to try is the wood-burning Zzip stove, which has the unusual feature of a battery-powered fan to force air into the fire, by all accounts creating a remarkable blaze for cooking. No toasting in the embers, alas, but then again stoves like this are for those times when an open fire is not the best option. Of course, this is a commercial stove, as is the Cabela model, and not a bit of home-brewed ingenuity. The most interesting design of that variety I've heard about was apparently made from an old shell casing, but sadly I have never seen proof of it.
