Have a bowling party or skating party. You can have a crazy hat day organize it with family memebers,friends and others. Pick a park or area where it is easy for everyone to get to and have snacks, arts and crafts, and games prepared for the event. You can get supplies like contruction paper, crayons, markers and other items to create the hats. Have a contest on who has the craziest hat design. And most of all have lots os fun!