These rolling ball sculptures are very ingenious and extremely inexpensive to make, the tracks and structure are made from bamboo skewers that generally are sold in packages of 50 or 100 for just a few dollars. This makes me wonder what other types of DIY structures could be made with this inexpensive material.
The chaotic nature of the construction makes the path the ball will take hard to visualize, watch the videos to get the full effect.
http://www.ohthebanter.com/rbs/