When I was in Girl Scouts, one of the things we made was the Monkey Ball Necklace. But as I was browsing the net about it, I see its called the Monkey Fist Knot Necklace.

I still have the 3 original necklaces I had from Girl Scouts, which inside of each of them I can't recall what it was, maybe a marble or bead. But whichever, Dr. Evil Jr. was still eyeing them up for his play toys.

I found this video,
its a mega example to show how to make one.
Link: How To Tie The Monkey's Fist

Here's some additional links about them:
Link: LoopyLacer - Monkey's Fist Bookmarks
Link: Monkey's Fist Necklace Kit