An interesting thread, and a concept that has been niggling at the back of my mind for some time. I spent a little time today aggregating everyone's thoughts, plus a few of my own, and came up with the following.
SHELTER
emergency blanket/s AND/OR
emergency bivi AND/OR
poncho/tarp
paracord
FIRE
firesteel/Waterproof-matches or similar
tinder (cotton-wool-vasaline, shredded-whatever, ...)
pocket stove (?)
TOOLS
knife/s (folder and fixed?)
folding saw or Leuko/large-kinfe (?)
torch
secateurs (?)
SUSTENCANCE
food (24 hours?)
water (24 hours?)
water purification items (?)
mug/cooking utensil
fork/spoon (?)
LOCATION
compass
map
GPS (?)
binoculars (?)
RECORD KEEPING/MESSAGING
camera
notepad and pencil
HEALTH
first aid kit
COMMUNICATION
mobile (cell) phone
signal mirror
whistle
CLOTHING
appropriate clothing
extra layer incase caught out overnight.
ADDITIONAL
fishing kit
sewing kit
Of course, what one takes out of the above would depend on location/terrain/weather and so on, but one could make up some pretty good basics for various situations.
I am also liking the idea, can't remember where I picked it up, of spreading the kit over a number of locations rather than having it all in one bag so you don't lose the whole lot if you lose that bag.
A neck pouch with the ultra basics sounds like a good idea.
Woz