So, tonight I was using osotogari to teach the kids about personal space (ma-ai). How do you teach a kid to define personal space? I tell them to hold their arms out in front of them in a big circle, as if hugging a giant invisible gorilla. That space inside their arms is their space. They own it. Anytime someone puts a foot down inside your space, you knock them down with osotogari.
The kids were eating it up, and my smallish 6-year old was able to consistently knock down much larger 8-9 year olds whenever they trespassed!
We also got to talk to the older, larger, more vigorous kids about control - which I defined as doing just the right amount to get the effect you want - not splattering uke's guts all over the mat, but not being lazy either.
[Photo courtesy of twostoutmonks]