A professor showed this to me in a ceramics studio. We set it up on a potter's wheel as a demo to learn how to center a piece and it was a fun day indeed. I later showed this to my 3 year old cousin and she flipped out.
What you will need:
1. An old record. (One that you don't mind scratching.)
2. An empty cottage cheese / yogurt container
3. One sewing pin
4. A way to spin the record. I am just using a pencil and spinning it with one hand while holding it in place with the other. This way takes two people but a "lazy susan", hand drill set up, or bearings make it easier.
Step 1: Make the Speaker
Make sure that the container is clean and then poke the pin through the center.
Step 2: Press Play
Spin the record clockwise and touch the pin to the inscribed grooves. In this example, one person is spinning and the other person is holding the "speaker" The analog sound is amplified and sure to inspire young and old audiophiles.