Research

This is an interactive piece that I found on openprocessing.com. (the link is at the bottom of this page).
What stood out for me with this interaction is that you, the interactor can hold the mouse button and produce lines tht rotate and move as you move your mouse, but at the same time a darker design follows suit but not in the same way that you yourself are making. Which then results in a more interesting interaction.

http://openprocessing.org/visuals/?visualID=31453