- Build a ZIF (zero-insertion force) socket interface for the ATMega, either separate from the Arduino board, or as a shield (I've posted before how this might be possible using a prototyping shield, and I think there may be manufactured versions for sale - I also know of an example floating around the arduino.cc website, maybe in the playground somewhere).
You could also try inserting a 28 pin 0.3" ZIF socket directly into the Arduino board. It's a little fiddly but totally do-able.
