If u want to buil one your self you can check my instructable here.
Here's the final result.
I first decided to do this project when I discovered how easy and cheap it is to display some scrolling text these days with just an arduino board and a led matrix. However, i felt that these cheap matrix ( like this one are somewhat small. I wanted something big that could light all of my city. I then decided to get real and do it in a 90X60cm cork Bulletin Board.
Pessoa extremamente inteligente, possui o dom da ubiquidade.