If you are a Disney fan getting married, print an extra invite and send it to Mickey Mouse or Cinderella and you will receive a letter of congratulations! You must pick one... I've been told they won't honor both.
Walt Disney World Info/Guest Letters/Letters to Mickey Mouse
P.O. Box 10040
Lake Buena Vista, FL 32830-0040
Cinderella and Prince Charming
P.O. Box 1000
Lake Buena Vista, Florida 32830