Purpose

Application of the Persistance Of Vision phenomenon, in a small box with a few pre-programmed messages like your phone number, "you're cute", ...
There is many tutorials on Instructables or even Ladyada also.
Trick will be to implement this WITH an ATmel chip but WITHOUT an arduino. Indeed, no need for big code, lots of I/O, Serial or usb, ... and it's a good occasion to start.

• LadyAda rules http://www.ladyada.net/make/minipov3/index.html