As we all work to lighten our loads, keep in mind to have the minimum basics in your "survival kit" to help you survive a night on the mountain. Some of the posts here have mentioned dropping some of the basics. So, make sure you always have on your person something for:
Fire: firestarters (cotton balls with vaseline, coughlans fire starters, whatever) and a couple ways to light them (matches, bic lighter, firesteel, etc.).
Shelter: keep the elements off and the heat in with something like a space blanket or other heat trapping item, a couple of 50 gallon trash bags that you can split and tape together or use as a sleeping bag, or an emergency rain poncho.
Water: pump or chemicals, something to store whatever amount of water one dose of your treatment will do (quart or gallon). Something that most don't think about is the bladder that you get a box of wine or coffee in, They are lightweight, have a screw on top to make filling and drinking easier than a ziplock bag.
Signalling: a whistle, an old CD to use as a signal mirror.
First Aid: something to stop bleeding or broken bones, plus your daily medications if you have any. This can be as simple as a baggie with your meds, some duct tape and some gauze pads to make field expedient dressings and splints (you can always find something stiff and straight in the woods to use for the splint), some pain killers, and something for the runs (immodium).
Food: this isn't really a necessity, but it will help with morale; just a couple of granola bars or some form of compressed food.
So, your survival kit can be as simple, and lightweight, as:
1 x space blanket
1 x box of matches
1 x bic lighter
3 x cotton balls with vaseline
1 x other fire starter
1 x whistle
1 x CD or signal mirror
1 x chemical purification drops (which expire over time, BTW)
1 x 2 quart coffee reservoir from Dunkin Donuts
1 x 15 feet of duct tape
3 x large gauze pads
1 x whatever meds you need
3 x immodium
8 x pain killers (2 days worth)
20 feet of paracord ('cause you can use it for all kinds of stuff)
This will all fit into one or two quart sized zip lock baggies and can be kept in the cargo pockets of your pants. No need to have stuff to cook in, or kill/trap/snare game, or catch fish. You are planning for and preparing for an unexpected night or two waiting for someone to find you or to walk back to camp in the morning.
Larry