tic tac toe board using maxim7219

i've been reading lots about arduino. Something I'd like to do is to make a tic tac toe board using a LED matrix with a Maxim 7219 chip. I want each 'square' (1-9) to use a small dual color LED Matrix to display one color for 'x' and the other color for 'o'. I want the 7219 to think that it is a 3x3 array (treat each small led matrix as one led.)

is this possible? I know this can be done with PIC. Any help would be appreciated. I'm thinking i would have the bridge the annodes together and cathodes together respectively to form 1 annode wire, and 1 cathode wire from each individual led square, then use those to attach to the 7219. my main question is about power. i plan on using a 6v wall wart mainly because i have a few lying around. I know I should attach resistor(s) to each 'square', but am having trouble determining what value to use. At any one time there could be 1 'square' lit up or all 9. Can arduino handle the intensity in terms of LEDs?

Something I'd like to add in the future, would be when there is no game being played is for each 'square' to light up in a random pattern. I'm thinking I'm going to have to use transistors

1 2 3
4 5 6
--- --- ---
7 8 9

Nice idea. Its certainly possible.

To make it think that its a 3x3 array, you'd just talk to it as if it was a 8x8 array with all the missing LEDs off.