I just remembered something from my last visit to DCA, searched the forum, and didn't see any threads on this.
I'm wondering, has anyone found the key under the mat at Muppet Vision? When you approach the ticket office to your left when entering the theater, there is a sign hanging from the window. It reads "out to lunch, key is under the mat" or something of the sort. Go to the door just past the window of the office and lift up the mat. There you will find the key!! It is of course stuck to the ground, but it's just Disney detailing at its best. Who knew you could find it in DCA of all places??!