To create our sound matching game, Zeke and I filled 2 of each of these eggs with different materials we picked out of the kitchen -rice, pepper corn, ect. We kept the colors the same, since I thought Zeke would be confused by eggs that looked different yet sounded the same. I've seen other people make this same game with film canisters, however, that all look identical. That would be ideal for an older child, forcing them to rely on sound only to match them. I suppose you could do the same with eggs, if you had enough eggs of the same color?
Either way, we had a lot of fun putting this together, as well as talking and playing with our shakers in the days after. They are great for shaking in time to music, playing memory, and just plain matching.