Visible crew/equipment: Near the beginning when the "cavemen" are looking around after hearing the noise from the alien, you can clearly see what looks like a sneaker print in the ice, in 35,000 BC. (00:03:00)
Visible crew/equipment: In the very first scene, the boom mic is very obvious at the top of the screen.
Visible crew/equipment: When Alan throws his father's broken radio into the box and he turns around to talk to the girl on the ladder, the reflection of a crew member wearing a white T-shirt can be seen in the monitor on the desk as the camera follows Alan. (00:30:40)
Visible crew/equipment: Just after Tarzan goes under the stone door, he finds the torches dropped by the bad guys. The flame from one of the torches is reflected in the camera lens, and was caught on tape. It looks like a single, unattached flame is hovering on the stone wall nearby. This is made even better when Tarzan picks up the torch and then drops it, the reflection follows his movements precisely.
Visible crew/equipment: When Jackie Chan is standing on top of the tower, and shouts "Who am I?", the camera starts to circle around him. When it does this, you can clearly see a guy in a white shirt standing underneath, and then hides away in the corner! It's really clear to see.
Visible crew/equipment: Several times during the "we're going to find a way" musical number the ankle part of the barney costume lifts up showing that the feet are separate from the rest of the costume and showing the ankle of the man inside the Barney costume it is most noticeable when Barney takes Marcella's hand and she steps on the platform.
Visible crew/equipment: Near the end of the movie when Alain is walking out of the fortress, in the background archway you can see what looks like a crew member with a backpack on walking past the set. (01:32:22)