Visible crew/equipment: The furry suits the "mole men" are wearing clearly show the zippers up the back when one of them is going down a well.
Visible crew/equipment: When Gort picks up Patricia Neal next to the flying saucer, you can see cables leading down to her body to keep her hoisted. (01:20:15)
Visible crew/equipment: Towards the the end, when Scrooge wakes up in his bedroom on Christmas day and is elated to know he is still alive, he goes over and looks in the mirror twice. Both times you can see someone in the mirror reflection in the background, possibly holding a script.
Visible crew/equipment: When the airplane flies over the area where the saucer skidded in and became buried in the ice, you can see the equipment used to clear the snow and smooth out the ice (at the narrow end of the ice). You can also see the tracks from the machine criss-crossing the circular portion from the aerial shots. (00:16:20)
Visible crew/equipment: When the rocket lands on Zyra, at the end of the landing, you can see the wire at the nose of ship guiding it. (01:19:15)
Visible crew/equipment: An absolute cracker from an epic movie - in one of the huge crowd scenes when they all go through the huge gates, you can clearly see a wee man in blue overalls eating a sandwich, he quickly realises there is a shoot on and tries to blend in with the crowd and enters through the gates.
Visible crew/equipment: Look closely the bottom of the screen when Rose screams seeing the leeches on Charlie: some black piece of equipment (it's not a stain on film or lens) pops up slightly and hovers a little before going out of frame again. (01:17:50)