Appropriate age group(s):
Preschool and Younger
Elementary School

Description of technique for dealing with temper tantrums:
I have 2 daughters who are 5 & 6. I've used this method since the youngest was 4 and it continues to work like a charm every time! They each have a kid-sized shopping cart that they bring along to the store! Sometimes I'll make a "list" for each girl with pictures of the items she is to "buy." Sometimes all I have to do is say (for example), "here's the cereal aisle - get a box of your favorite cereal." And sometimes they just follow me around and add to their carts the items I hand them. I have never had a single problem since we began to shop this way. Obviously, you should choose a time when the store isn't crowded, but most of the other customers find it charming - certainly more charming than a tantrum!

Other suggestions or comments:
I think this method is probably best for ages 4 - 6.