Lord of The Rings: Fellowship of The Ring - Wrong Arm
When they are in front of the 2 big statues, the statues raise their left arms. When they pass them and you can see them from behind, one statue has raises its left arm and the other its right arm.
This is a big one people usually take for a mistake, but Lucky is right. The statue on the right from the front (beard) is clearly holding out his left hand like the statue on the left (no beard). After they pass and it shows from behind it looks like beard is now holding out his right hand, the opposite of no beard. But beard is holding a sword in his right hand. This turns his right arm in to his body, and sticks out his right shoulder. Therefore from behind it appears as if he's now holding out his right hand, but what you're really seeing is his left hand extended past the curve of his right shoulder.
Now if you can follow that with all the 'lefts' and 'rights' I've thrown in, I'll give you a hand. ^_^;;