I posted these links in another thread but thought they'd fit better here. Show these to your kids and explain to them what they mean. I remember growing up and seeing these videos mixed in with Saturday morning cartoons. I wish they still were.
http://www.youtube.com/watch?v=p0LmYEjXNIg&feature=related
http://www.youtube.com/watch?v=AhdmDDBjco0&feature=related
http://www.youtube.com/watch?v=SQdDjBAJt7c&feature=related