It’s quite simple. Dress up your kid for Halloween (and yourself, for that matter), take a picture of yourselves and send it to them. If you win, you get a bunch of horror DVDs - how apropos. There are winning categories for both kids and adults and the movie titles are appropriately rated (i.e. Gremlins and Monster House for kids and Nightmare on Elm Street - Box Set, and The Exorcist for adults amongst others).

Sited Links:
Cinematical | Third Annual Halloween Costume Contest