I don't know how I missed this every time I've ridden on tower of terror, but in the upstairs loading area there is a drawing of lines forming a "door" on the wall that is a reference to the Twilight Zone episode "Little girl lost"
In that episode a girl goes into annother dimension through her bedroom wall. This episode was parodied by the simpsons in a halloween episode where homer goes into the 3D dimension.
In the line for the ride you can even hear her calling for her dad! (It sounds like the audio was taken directly from the episode!)
I don't know how i missed this!! It was a cool find for me and now I wonder if there are references to other Twilight Zone episodes in the ride line?? Anyone know of any more?