Great thread. I've picked up some good ideas! I've got a considerable amount of time in the mountains in the weather. I'll keep some stuff on me and split the rest into a pack. most of my must-haves seem like they've been mentioned. but here we go:
Folding wood saw
pocketknife, I carry one on me and one in the pack
three forms of firestarters - I gotta be able to start a fire
road flares
styrofoam cups
again, I carry two, with my backup t-shirt packed inside of them. styrofoam will not burn when filled with water. you can boil with it.
flashlights, I carry 2-3 led's or extra batteries
Food
First aid kit
electrical tape
emergency blanket, and/or small tarp for making shelter
GPS
avalanche gear if your area dictates it
water- I carry two 16oz bottles + 2L in the camelback
Fire is my first priority, followed by first aid supplies and some kind of food. the road flares are a lifesaver. not only can they be seen for miles at night, and draw a lot of attention, but they will also allow you to start a fire when your fingers are too cold to strike a match or fumble with a lighter, not to mention you can just about light a tree on fire with them. GPS is a no-brainer. flashlights are just necessary. they are also another item that can be used to lure searchers in at night, when it is dead silent and the horizon is dark. I'd never underestimate the usability of a knife. a disposable shop towel or two make great firestarters, can be used as toilet paper, and will not stick to a wound. a good electrical tape is water resistant, works great for making bandages, and is kind of like duct tape in that you will find many uses for it. I think crazy glue was already mentioned but that stuff is great for sealing up a deep cut. if you cant pack a tarp to make a shelter, you can at least huddle up inside of an emergency blanket and be fairly impervious to wind or snowfall. makes it harder to keep a fire going, though.I think the tampons are a great idea. I'll start carrying a couple.