One person claps, then the next to the right (left in the northern
hemisphere!) and then to their right, and so on. Once the clap gets all the way
around keep it going but say "Faster". Keep it going faster and faster until the
clap zips around the circle almost instantaneously.

Variations include:

Adding a second clap in the same direction, or in the other direction.

Using a hand squeeze instead of a clap (watch for it getting lost).

Doing
it as a wave (raise arms slowly up and down once, person on right starts just
after you.)