One of my favourite subjects. My survival kit is now just a few oz, and is about the size of two cigarette packets. I live in one of the wettest temperate climates in the world, easily 10 to 20 feet of rain a year (yes thats right - up to 8 metres). Gas lighters of any type can be a problem in a survival kit as over time they develop "issues", and just when you need them, they don't go - don't ask how I know this !! I use plain old matches in a film canister, and back that up with a few of the wind/waterproof supermatches.
The two most important items in my kit for getting a fire going are a bit of plain old motorcycle tyre tube, cut into the size of large rubber bands, or in one piece (mine is the outside wrap of my survival kit, and there are usually a few spare bits in my bum bag too) and knowlege/practise (oh bugger thats three things). Even in the wettest bush (forest) here you can always find some burnable stuff on the dry side of old trees, although it often takes a while, and requires experience in knowing where to look.
There is a potential problem in relying too much on "stuff" that may or may not be in your survival kit as every unexpected night out is different. Knowlege and confidence are much underated "tools" in dealing with problems in the mountains.
For example recognising early that you will not be back with your buddies for the night is real important, then you have time to seek shelter etc (getting out of the wind, and getting a fire going are 10 times more difficult after darkness falls), and you are much less likely to make further mistakes. Most people who die in our mountains don't just make one mistake, they usually start with a small one then compound it - mostly by getting hypothermia, which generally stuffs your decisionmaking capabilities anyway.
