Stone Arrowheads: You can pick these up online and with some thread and sticks, make great hunting and defense companions. But a word of caution - be smart about the size of the ones you try and put in your carry-on.
Mini Flashlight: These things are amazingly powerful and have great battery life. Plus, they are super cheap. Tuck two or three away in your carry-on. And throw in a head strap, too.
Personal Locator Beacon: Get your signal on and help will find you in no time.
This is how my boss told me to park Fed Ex trucks. He's been fired for a while now.
DONT THINK WE HAVENT NOTICED ALL THE GREAT WORK YOUVE BEEN PUTTING IN GUYS
Glow Sticks: Particularly the ones that can be made into bracelets and will tie around things. A must for trying to be located by rescuers at night.
This looks bad, but you should be impressed that I delivered two packages and two water jugs in one trip.