I'm developing "Britable" a mini system with 25 shiftbrite leds in a 5x5 array. You can find all the information at http://www.neuronasmuertas.com/britable (sorry, it is in Spanish) I'll post the code soon.
The system has a character generator (still in the works, only numbers by now) Also, it uses a Perlin Noise algorithm to display smooth colour transitions. Using a push-button, you can change the scene. Currently, there are twelve different scenes / animations.
Sometime in the near future, I'll attach a couple of sensors and / or some kind of ethernet shield / xbee to get information from external sources.
Yep, it's cheap. I bought it from a plastics store in Madrid. You can cut the grid with a pair of pliers, and then file the stubs (if you feel up to it)
It's diffusing grid typically used in drop ceiling fluorescent lighting. Around here, you can get it at any Home Depot in the lighting department. Costs less than 10 bucks for a 2x4 sheet.
