Visible crew/equipment: After starting their four day journey through the long dark of Moria, a few shots later Gandalf pulls on his hat brim, and just as he walks (with Legolas close behind) to his left (towards the viewer's right), up some stairs, the black electrical cable leading from the staff to under the robe's left sleeve is visible.
Deliberate mistake: When Sam and Frodo are in the field with the scarecrow, you can plainly see a car cruising past in the distance, from right to left. Further comment - there are two different shots which show the car moving from right to left. One starts at the top right distance, and in a shot a few seconds later the car has traveled down the road a bit and is more easily visible. Complicating matters is that the dust thrown up by the car looks similar to smoke from a chimney in the right distance, making some people think it is just the chimney. But chimneys don't move, and the smoke from the chimney is separate from the moving vehicle. [It is deleted on the DVD, but you can still see an obvious bit of image fakery on the hill just left of the smoking chimney. One can see the hill, tree, and surrounding area move up and down and shimmer slightly where someone has done a cut and paste to cover up the auto. The "car inclusive" scene appears on the National Geographic documentary, "Beyond the Movie The Lord of the Rings: The Fellowship of the Ring." Also, watch the music documentary on the Extended DVD - when it shows this scene the car is still in it. Bizarrely, in his commentary Peter Jackson said he never saw a car and doesn't know what people are talking about, but the production/post-production team say in their commentary that despite not thinking anyone would be able to see it, they took it out anyway.]
Continuity mistake: When the hobbits are hiding under the tree trunk from the Ringwraith in the beginning, you can see space to the left and right of the tree above them. Logically when the Ringwraith walks past the tree you would see it on the right side of the tree first, then on the left, but you don't - it looks like it walks out of the tree instead of behind it. [Confirmed on the commentaries - Elijah Wood asks his fellow actors if anyone spotted the mistake: 'It kind of magically comes out of the tree'. Sean Astin: 'You mean it doesn't pass from the other side?' Wood: 'No, it comes out from the centre.']
Gandalf: Confound it all, Samwise Gamgee, have you been eavesdropping?
Sam Gamgee: I ain't been dropping no eaves, sir, honest! I was just cutting the grass under the window there, if you follow me.
Gandalf: A little late for trimming the verge, don't you think?
Sam Gamgee: I heard raised voices.
Gandalf: What did you hear? Speak!
Sam Gamgee: Oh, nothing important. That is, I heard a good deal about a Ring, and a Dark Lord, and something about the end of the world, but please Mr. Gandalf, sir, don't hurt me. Don't turn me into anything... Un-natural.
Frodo: It's a pity Bilbo didn't kill him when he had the chance.
Gandalf: Pity? It was pity that stayed Bilbo's hand. Many that live deserve death. Some that die deserve life. Can you give it to them, Frodo? Do not be too eager to deal out death in judgment. Even the very wise cannot see all ends. My heart tells me that Gollum has some part to play yet, for good or ill before this is over. The pity of Bilbo may rule the fate of many.
Question: In the scene where Gandalf and Saruman are fighting in the tower Saruman takes Gandalf's staff and sends him to the top of the tower. What happened to Gandalf's staff? When he escapes he somehow gets his staff back and uses it the rest of the movie. Is it another similar staff, or am I missing something?