Pocket Clip or Keyring

A light only helps when it is already on you, not in a kitchen drawer.

USB Rechargeable Cell

Carrying spares fails, while charging from a cable you already have works.

One-Handed Switching

The other hand is holding the thing you are trying to see clearly.

Useful Low Output Mode

Most daily tasks need a little light up close, not a blinding beam.

Tough, Pocketable Body

Keys and coins scratch, and a carried light gets dropped on concrete.