Thanks for the welcome.
James, LEDs is exactly where I was going to start. Planning on making an LED cube first.Make a Pocket LED Cube - YouTube
But one thing I thought about is instead of lighting up an LED by grounding one layer and powering one column (3 led's), instead if you ground one layer (call it plane X containing 9 LEDs) then power plane Y and plane Z (each also containing 9 LED's) then where the 3 planes meet there would be one LED that is grounded and getting powered twice. Using an AND gate you could make sure only that one turns on. This means instead of using 9 outputs for power (one for each column) you would only need 6. (3 for plane Y and 3 for plane Z.) Not a big deal for such a small cube, but if say I wanted to do an 8x8x8, then using their logic I'd need 64 outputs (8 X 8). Using mine I'd only need 16 (8 + 8).
Well it works in my head. Other than one quick sketch I haven't diagrammed it out yet. I'll work on it this week/weekend.
BTW, what do most people do after they create a project they want to keep? Would I just order something like a Mini and swap it out for the Duemilanove so I can keep it for prototyping?
Thanks.