A Hidden Mickey is a representation of Mickey Mouse that has been inserted subtly into the design of a ride, attraction, or other location in a Disney theme park, Disney properties, movie or other Disney product.
Hidden Mickeys are everywhere. The book above list the "official" Hidden Mickeys. Searching them out is a great way to spend the day - If you do Free Disney or the Monorail Crawl especially so! I am on the lookout for Hidden Mickeys Hope you will join in the fun too!