Small, cheap, and useful

As an admin, I have to swipe my ID through 50 doors a day. We horde promo ID tag zip strings. They're a little plastic clip with a retractable string in it (sort of like the ones the Janitor uses for his keys). The plastic part hooks to your pants, and the string end hooks to your ID. You pull, swipe, and let go. No fumbling, no fuss.

The plastic part has the logo on it.

For the less physical security conscious worker, how 'bout a multi-tool (the LeatherMonk)?

-OzzyOsbourne