There are a number of possible demonstrations with rotation and turntables.
Using a small record turntable, coins can be placed at various radii--they will slip off at some radii and/or speeds and not others. It can also be used with the parabolic water surface. Unfortunately, at present (2/2000) none of the small turntables are working very well.
There is also a large rotating table, about 1.25m in diameter. A video camera with transmitter is mounted above it and rotates with it, allowing the TV monitor to show events in a rotating reference frame. You can see coins sliding out linearly, etc.--use your imagination here.