EDIT: Someone on IRC pointed me towards EEPROM where I could give the board a "serial number" and tell them apart. Leaving this here for future reference, hopefully it'll help someone else someday.
Ok, short explanation. I've got 3 devices (Arduino + xbee + RGB LED) I'm trying to get them to talk to each other and use the colors to show how far they are from each other. (And i'm a total newbie btw)
This means they need a "master" color. (IE. #1 Rgb, #2 rGb, #3 rgB) but I would rather not write and edit three different scripts, so I figure I should be able to add something like a resistor to each unit to mark them as different that I can check via script. But I'm not sure of the best way to do this. I have all the analogs and 5 digital pins free.