I almost always have two or more of the following:

flashlights
first aid kits
pocket knives
hats, gloves, etc
backpacks
duct tape
rope
whistles
lip balm


It's interesting, because I've given "extras" away to people when they've really needed it -- and then went out and bought replacements to keep on hand.
_________________________
I love to go a-wandering,
Along the mountain track,
And as I go, I love to sing,
My knapsack on my back

Current kits: http://forums.equipped.org/ubbthreads.php?ubb=showgallery&Number=241840