with all this talk of incomplete butane combustion, i think i might have a solution for all the flavor purists, and for those that are concerned with the butane
have any of you thought of using an alcohol lamp? it is a wick based system that will burn ethanol or isopropanol, which are a lot less expensive and more pure than butane, and it will burn very clean, i used to use an alcohol lamp for my combustion waterpipe before i lost it (the lamp, still got the pipe) the taste was much cleaner than a bic, and it was only a little more difficult to use, but much better quality
in fact, this is what im planning for a mobile vaping solution, the only real concern is having an open flame, if your reasonably careful and put it out between sessions (cramped spaces might be a problem too
alcohol lamps look something like this, it fits in your hand and is spill resistant, it leeaves soot just the same as butane, but it doesnt leave the hydrocarbons associated with low quality butane or poor refinement