gyroscopic motion is what stabilizes a Frisbee, makes a gyroscope neat and useful, and allows people to ride bikes

For some reason beyond me a spinning object resists changes to its axis of rotation (it has something to do with moment of inertia I think but I don't know for sure)

An easy and fun test of this concept requires a computer which you can open and tinker with:
1) turn off and open the computer
2) unplug the IDE/SCSI cable from the hard drive (but leave the power cable plugged in)
3)hold the hard drive in your hand
4)turn the computer on
5) try moving you hand in different directions and feel the pull on it

Neat, huh?

So what! Now comes a practical application...
Teaching a child to ride a bike:
1)explain to the child that the spinning of the wheels makes it easier to balance on the bike so the faster they go the more easily balancing becomes.
2) take them to a long (but not very steep) downhill stretch and let them start at the top (so even if they are too confused/scared to pedal they will have the wheels spinning fast enough to stay up right)