I really enjoyed the Maker Faire this weekend in San Mateo, California. One of my favorite exhibits was the absolutely-mesmerizing Sisyphus V kinetic sculpture by Bruce Shapiro. It consisted of a huge sand table with a 2-axis robotic controlled magnet underneath it guiding a steel ball to make beautiful, continuously-changing designs in the sand. The sand table was a couple feet high and probably 10'x10' square.
Bruce Shapiro does a lot of this robotic controlled artwork. He has a website called "The Art of Motion Control" at www.taomc.com.
I put a short video up on YouTube to give the idea of what I saw. I borrowed "Celestial Soda Pop" by Ray Lynch for the music.