I liked the author's prior book on meditation for kids, Peaceful Piggy Meditation, but I think I like this one even better. It is funnier, and teaches a meditation that many preschool and elementary age children will love. The story centers around a young cow/boy who has had a VERY bad day (thus earning him the nickname 'moody cow'). He has a bad dream, his sister bugs him, he misses the school bus, he gets in a bicycle accident - like I said, a VERY bad day. And he gets VERY angry. To help calm him down, his grandfather helps him make a 'mind-jar', where sparkles swirling in agitated water represent his angry thoughts. Then he 'meditates' on the mind-jar by watching it until all the sparkles settle peacefully at the bottom. At that point, of course, he is feeling much better himself too.
Not only is this a great way to introduce meditation (instructions for the mind-jar are included in the back), but it also provides a way to talk about difficult emotions, and the situations in kid's lives that make them feel that way, in an open and non-punitive fashion. And it's appropriate for parents, teachers, and kids of any religious (or non-religious) background - meditation is not presented within a religious framework. Highly recommend!
EDIT 7/9/10 - I came back to edit this review after reading some of the other reviews. It is true that there is a lot more anger represented in this book than others, and that moody cow's expression of that anger - and his sister's - are pretty aggressive. And the mother's initial reaction to the behavior is punitive. But personally, I feel it has a fairy tale feel to it, because the characters are animals, and so these actions trigger discussion, but aren't presented as models for behavior. My own kid's did gasp the first time we read this book, when he broke the window, in the way they might gasp at a dragon battle or whatnot in another kind of story. I think the value is in triggering discussion, and letting kids feel like we all make mistakes, as opposed to trying to 'regulate' what they are exposed to. Of course what age to do that at is a personal parental decision.