Tip: Cast Members will sometimes grant special requests.

One time we had a Fastpass for Tower of Terror and the return time was 11:00-11:50 am, but we really wanted to see the Little Mermaid show at 11:00 without standing in line. We couldn’t get a Fastpass for that because we already had one for Tower of Terror, so we asked the cast member at the gate if he had any for the 11:30 show. He said yes, and gave us three of them. So we watched the Little Mermaid show, then went to Tower of Terror immediately after without standing in line! Obviously, this wouldn’t work all the time, but cast members will sometimes accommodate special requests. Ask and ye shall receive at Disney World!