I used something like this at a music festival, after they'd banned every other type of stove. I found a lot of nerds on the internet who all raved about these little things and after using them I was inclined to agree.
It's the simplicity of them, they feel so peaceful to use. Yes they take a bit longer to boil than everything else but who's rushing while camping.
Just putting the finishing touches on GNAW (Gnaw's Not A Wheel)