Right in the middle of Hollywood Studios you'll find a larger-than-life Sorcerer's Hat that is hard to miss. Since it's introduction on September 28, 2001, it's been the subject of a lot of debate but aside from a discussion on it's future, the Sorcerer's Hat has some history to it as well.
The Sorcerer's Hat is a 122-foot tall blue and gold hat based on the hat Mickey Mouse wore in the film Fantasia. In the film, the hat gives Mickey the magical powers of the Sorcerer Mickey is working for when he wears it. During the 100 Years of Magic celebration, Imagineers added the giant Sorcerer's Hat to the Great Movie Ride courtyard to serve as the park's icon.
During the 100 Years of Magic celebration, Disney had interactive kiosks underneath the Sorcerer's Hat where guests could learn about Walt Disney's life and career. When the celebration ended in early 2003, the kiosks were removed and has since sold pins.
Officially, the Sorcerer's Hat serves as Hollywood Studios' park icon, since prior to the hat, the park's icon was the Earful Tower water tank, located in the Backlot area of the park. Disney wanted to have a more central park icon like the other parks had that was easily spotted from nearly anywhere in the park. In addition, the hat represents "the magic of show business and the entertainment wizardry of Disney". At least, that's the official explanation.
The long-rumored reasoning for the Sorcerer's Hat being added (and staying as long as it has) is Disney had to block the Great Movie Ride's Chinese Theater facade from being perceived as the park icon as well as appearing in promotional material for the park. It's been speculated that Disney, for some reason, was restricted by the owners of the real life Chinese Theater building in Hollywood from using the building's likeness in promotional material so Disney had to block the view of the building from any and all promotional materials. If you pay attention to photos, video and art work that comes out of Disney these days, the Great Movie Ride facade is rarely shown.
So there you have the official and unofficial reasons why the Sorcerer's Hat is there. Here are some quick facts about the Sorcerer's Hat