Keys, house Keys, car Leatherman Wave (the old model...the new one isn't as good) Phone, dumb, RAZR AA Maglite (no not the LED kind) Fire or the materials with which to make fire. Usually a Zippo, or Bic Classic lighter. No human should ever be without the ability to make fire at a moment's notice. In event of societal collapse, civilization can be restarted with a knife and fire. :) I used to carry a nice USB drive on my keychain, but I kept breaking them. I actually still have one attached, though it doesn't work, as it makes a nice keyfob.

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