For design I made an instilation of 2500 plastic army men all painted bright yellow and blocked off an 11'x11' square in the main hallway of my school. The concept was simple. You either have to go around or walk through em. Nothing more than little pieces of plastic, but they will send people walking out of their ways to avoid them. People took a little coaxing before they were willing to walk over them, one guy jumped em, but once the seal was broken by the most unexpected lady it was on.
Interesting experiment. We like to avoid the ideas of what army men do in real life too, but we have little yellow ribbons that say we don't.