Do you remember the Gravitron at OMSI? I loved that thing. It was a tall, rectangular space enclosed in glass that housed steel framed track that looked like a miniature roller coaster, where silver balls would travel. There were numerous different tracks, and little kids like me fascinated, watching the balls travel this way and that, going one way and then all of a sudden going another, with all of the twists and turns, the steel arms that would flip over and pick up a ball to take it to another track and then rest to wait for the next; the wheels that looked like miniature ferris wheels with spaces for the balls and when it was full it finally overturned the balls onto tracks to keep falling, down, down, down. When they got to the end, there was an elevator that brought the balls back to the top and it would do it all over again.
I was reading Dooce this morning and she featured this video. She's right, it is absolutely amazing. It is better than the Gravitron, and now you know how big that is.