first get some ginger bread cookies and some napkins, then buy some chocolate chips. Fold the napkins to look like diapers and place them on the cookies. In only two of the diapers put one chocolate chip in them to represent a dirty diper. pass them out to your guest and the two that get the dirty dippers win a prize. Its so much fun and does not cost a lot. If your on a budget that will come in handy.