I really want to build one of these, sadly I have a lot of things going on, so not sure when i will be able to get around to it. The difficulty, as I see it is the isolation of each row. I will be curious how you work that one out.
Thanks again crossroads, I may build one of these, but mostly I really like the idea. Nice work that.
After typing this post, I had a crazy idea. RGB LEDS. It would need a total of 25 control lines. I suppose you could do bi-color LEDs using a total of 20 control lines.