For the camping version of the button toy, Hubs made the button out of piece of our firewood. It was a biggie too! And the string is glow in the dark.
Hubs actually ended up making a few of these because they split pretty easily when he drilled the holes into them.
Finally, here it is in action. Similar to the yoyo, it takes practice for the little guys to find the right rhythm of pulling the string. Eventually, with the right pulling technique, you can really get it going.
Bonus: upper arm workout.