Idling is a very useful skill. Picture this: you have to wait for a car at a stop sign, but rather than dismount, you just idle in place for a bit before continuing merrily on your way. It's fun, and it looks pretty impressive, too.
A good way to learn is by hanging onto a fence or a pole to practice rocking in place until you get the feel of it. Then try idling by yourself. Next, try riding forward, then idling in the middle of riding, and then continue going forward.
Idling can also be a cool way of turning around - each time you idle, turn a little so you end up idling in a little circle.
One-footed idling is another skill. We have included that in the "Riding One-Footed" section. :)