Interesting twists on Piet would be:
* animated piet programs - perhaps where the incrementing the PC would also increment the frame of animation, or the current frame of animation is another property that can be manipulated.
* writing an editor to make it easy to convert works of art into Piet programs.
Or similar: Piet Gifs: every n instructions the program changes but the IP remains. This feature shall be called polymorphism.
Hey, my "Alpha" program is still there! I remember learning Piet for the Perplex City ARG (2006/2007) and thought it was an amazingly weird language. Thanks for the memories!