1. Glasses
    My vision isn't that bad but it's good form to wear them all the time.
  2. Watch
    Time is the great equalizer.
  3. Lip Balm
    Grow up somewhere dry and you'll view this as a necessity.
  4. Wallet
    ID and liquid assets.
  5. Keys
    Even if I'm not driving, even if someone else has keys, I always have my own.
  6. Knife
    Doesn't need to be a sword, just an immeasurably useful tool. But only present in appropriate situations.
  7. iPhone
    Infinity in your pocket. Access to information, research, communication, or a pretty decent camera.
  8. Pen
    A newish addition. A good pen goes a surprisingly long ways. Only fountain or space pen (look it up).
  9. Camera
    Not necessarily always on my person, but if I'm going anywhere even mildly interesting this is something I'd love to have on me. Sony NEX-6.