Kris Harzinski's Waiting Light.

Annoyed at having to wait in line, Kris Harzinski created this "Waiting" light that you wear around your waist:

When you turn on the switch it shines a bright orange color behind the bold, black letters that proclaim, “WAITING.” Perhaps it will make waiting less mundane. At the very least, it will give you something to talk about with the person standing or sitting next to you. It may even help whatever it is you’re waiting for find you.

http://www.krisharzinski.org/Pwaiting1.html - via Notcot