Another good example is the advertising campaign of PilotFrixion 60” pen. This pen has an eraser on the opposite side. The idea was to link the writing/drawing process to the evolutionary process. Like evolution, the pen can erase unnecessary stuff. They made an animation to show the main idea. The animation shows how this pen will help you not only to create drawings, but at the same time gives you the opportunity to erase, redo, 'evolve' them.