Any tricks / ideas out there?
A few weeks ago we had the discussion how to put the sourcecode of a sketch into the Arduino. This ended in adding a unique reference to the source in the code by means of an UUID which is in fact just a 16 bytes unique number. See - http://arduino.cc/forum/index.php/topic,64193.15.html - for the whole discussion.
This technique might be usefull for you. I have not tried to access the UUID array from the sketch, should be possible as it is just access to progmem ...
Rob