We bought a 4″x4″ and screwed on some blocks of wood at the ends for stabilization. It was a hit. Especially with the 18 month old.

Note: Our piece of wood didn’t seem to have any splinters. Also, it’s a bit cumbersome to have laying about. I just knew I was going to end up tripping on it, so it’s banished to the garage when not in use.

Other than that, it was well worth the $8 to see how excited the kids were going back and forth. We got to watch Ero master the one foot in front of the other move, which puzzled him at first and excited him to figure out. Good times.