I really like your idea.
I'm building a weather station using arduino.
The main display of all the weather data is to be my PC.
The PC is on only for short periods so for most of the time
the arduino will just be a box with blinking lights.
I did not have many digital pins left but with your circuit I
think I will add some hex display to make it more entertaining.
I may write it as a small class as I did for the sd card:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1259789744/0#0
I assume your idea is competely open as mine are but I
will Include your site in the comments if you wont.
Or not if you dont.
I will post the details on this forum.