Here at our little library in Massachusetts we have invited Mannersmith Etiquette Consulting to come in and give our young patrons a "pre-holiday" refresher seminar. The seminars are specifically geared to children and run only 45 minutes to an hour depending on the childrens' ages.
We happen to have a very generous "Friends" group who provided funding for the two sessions; one for Preschoolers & Kindergartners and a second session for 1st through 4th graders. Each session was $100.
Mannersmith was delightful in every way (they come highly recommended from everyone from The Washington Post to Martha Stewart). They even included handouts so that the children could take them home and share their experience with their families.
Unfortunately, because of the nature of the program, Mannersmith did require us to limit each session to 15 participants and (rare for us) required pregistration. I do think, though, that the positive feedback from so many parents (even those that did not sign up) far outweighed the minor annoyance of the few that we unable to secure a slot.