Late to the party and will read through it all, but here are my suggestions:
Boy scout "hot spark" for a lightweight low cost one. Its small and fits on key rings, compass lanyards, or survival necklace
Coughlan (spell?) has a bigger one for about $5 thats stout and works well.
And... Bic lighter or similar without the safety thing in the striker wheel.
I find it is easier to start fire with fire, but watching a hot spark igniting a vaseline soaked cotton ball during our survival segment in youth fire arms safety convince me to carry the cotton balls.
