There seems to an agreement of sorts developing around a three device array - lighter (usually a Bic or Mini-Bic), matches(usually storm proof of some variety) and a steel/striking rod combo (various types here). All three are relatively light and compact, and fairly cheap,
especially when compared to their potential benefit.

KenK proposed the Storm Candle Lighter - unfortunately, the link he provides states that REI no longer carries the item. I think I have seen it for sale just a few months ago, so it might still be available.

What to do if you are disabled or impaired and a fire is imperative? Definitely a question worth considering and practicing a bit before hand..

Esbit, cotton balls, Tinder Quik, and Tinder Cards are most frequently mentioned for tinder, just as important as the lighting device. With luck, good tinder can be found, but don't count on that completely....