My granddaughter and I have operated this event (not really a contest) for the past 5 or 6 years. The format is easy and encourages kids to get on the air. It uses an easy exchange of Name, Age and Favorite Color. After that exchange you can have the kids chat a little or just move on. You can have more then one kid there and let them all operate a little.
There is a decent amount of activity and well worth operating this event. The kids really enjoy this.
Oh and by the way my granddaughter got here license earlier this year and is now KI6KOI and we will be operating again this year.
http://www.arrl.org/qst/2007/12/kidsday.pdfhttp://www.arrl.org/FandES/ead/kd-rules.html