Originally Posted by **********

I forget what its called, but I know what you mean. It's based on the old persistence of vision illusion (http://en.wikipedia.org/wiki/Persistence_of_vision). It is 1, 2 or 3 rows of light that display words or images that are only visible when they are moving or spinning.

A company tried to turn this into rims for cars a few years ago.



Talk about tacky...

The illusion is called something like

Originally Posted by KRosh

Programmable LED message display?