Did you play string games when you were a child? My mother taught me how to play Cat's Cradle when I was about 5 years old, and I'm now having a great time playing it with my own son. It is such a quick and portable game that we've been playing it wherever we go.
I had to look up the history of Cat's Cradle, and was surprised to find that this clever game is played by children EVERYWHERE. Its origin is unknown and it has been found in wildly diverse indigenous cultures from the Arctic to Europe to Indonesia. It is probably one of the oldest games in the world.
1. Buy a pie from a nice bakery that ties string around their pie boxes.
2. Carefully untie string, eat pie, reserve string.
3. Cut a piece of string that is about 5' long.
4. Tie the two ends tightly with a square or granny knot and trim extra string.
5. Learn to play, or if you already know how, teach someone!
You can find plenty of instructional photos and videos online, but I recommend carrying your string around and asking people if they know how to play any string games.