Thanks for the response. I have seen that done, plugging, unplugging, but I was looking for a more elegant way. For example if I want the ATtiny to communicate with UNO, I would be unplugging programmer pins between the Uno and ATtiny only the reconnect them again to the Uno in diff manner. I would prefer to do neither and just hit a button/slide a switch and lo and behold by programmer pins are disconnected between Uno and ATtiny, and my shield is now running with ATTiny.
I would ideally like to program and run the ATTiny on a shield without all the plug/unplug.
Thanks