Have a birthday party in a mystery theme. If you have ever played the game clue, make everyone dressup like the clue characters then play the game. Play the clue game like a big clue game but if you don't have a conservatory use the basement or outside patio. play ordinary games during the party but have people try to figure out who killed Mr. Body. It was great fun at my friend's party. (you won't know how to do this party theme unless you have played 'Clue'.