Though it is a classic, it has got a lot more effective with the introduction of rare earth magnets. You can investigate how the voltage produces is affected by where the magnet is moved, how fast it is moved, how strong the magnet is and how many turns the coil has.
To make the experience more intuitive this version visualises the flow of electricity with a flow of led lights.
It is one of the most effective exhibits we have ever built, and even if you know what is going to happen it is somehow still surprising whether you are a 2 year old, or a physics grad.
To demonstrate approximately how a mass spectrometer works for an outreach project at the Museum of Science and Industry in Manchester I built a ball bearing deflector. It works by having a ramp, that you roll ball bearings down, and at the bottom they go past a magnet. The small ball bearings are deflected more than the large ones, a bit like the ions in a real mass spectrometer. Apparently it went down well.