Hi Allan,
This i just a thought, If you are interested in just something compact and which is quick and easy for just a boil up or to heat up something simple, try Google , Penny stove,
I came across these a while ago and was quite intrigued with the simpleness and compactness of these easily constructed homemade devices,
I actually got around to knock one up out of a coke can and it worked quite well,
Apparently the are a favorite thing for walkers and hikers etc in the states.
Cheers ,
Winston66