check out the development blog of 8x8: http://campingsex.org/8x8
right now it is basically a 8x8 pixel screen of 12V 10W incadescent lamps. i have writtten code for music visualization, movie playback, txt scroller and more for processing, using arduino and the maxim7219 LED controller as the interface/translator.
although this is still a work in progress i'm posting this now. i haven't got the time to develop further on the project right now :( but i would appreciate feedback and comments, for further development in the future. either here in the forum or directly on the blog as comments.