I thought folks might be interested in seeing how the internals of a motor works.

Here's an animation of a 4-pole outrunner turning (you have to click on the thumbnail for the animation to start up).  The outer arcs are the business ends of the permanent magnets, the oddball-shaped inner pieces is the armature.  Red means a north pole, blue means a south pole, gray means an armature segment isn't energized.

Study it for a while, and you'll see that each armature segment switches polarity in a way that means it's always pulling a permanent magnet in the right direction to make the motor spin -- this is how the motor generates the torque it needs to keep the prop going.

I'll bet that some of the audience were pretty animated, too, for a bit.

That's one way to encourage the audience to pay attention.