Hoping to start a list of little "secrets" that people found around WWoHP, but people who haven't visited might want kept a secret, or not. So if you don't want it spoiled please don't read on....
Examples might be something simple like finding the Weasley's Ford Anglia in line for Dragon Challenge, or the house elfs in Three Broomsticks and Hog's Head.
I tried paying attention, but I'm sure there are tons of little details that could be discussed that others might want to discover on their own.
Deb - you know what's funny....on our third trip on Forbidden Journey I finally realized they used our faces! The first and second time I kept seeing a face which looked so similar to my SO that finally I realized they took our picture and used it for that effect! DUH!!
I wasn't sure it was us, so after the first time, I asked our kids. Of course, they are teenagers and have much better eyesight, and they said, "Yes, mom, that was US!"
It is a very neat effect, though, seeing your faces in the gray mist being "sucked" away by the dementors! And like you, I noticed my family's faces before I noticed mine!