BIC all the way. I have and carry a couple of the butane lighters. I trust the BICs to work and I like that you can see the amount of fuel remaining. I also like to use them to read wind so I have way too many with my. I figure they weigh nothing and I don't want to ever have to start a fire with a spark if I don't have to.
If it's an emergency, using a spark is the LAST thing you want to do. You want an inferno and you want it NOW.
If you want an inferno and want it now, that leaves the road flare option posted above. I've carried flares or a flare gun in my pack for years. You can start a fire with a flare gun, but what you're shooting into must be able to absorb it or it's going to ricochet.
