Trivia: 5000 cubic metres of vegetables and flowers were grown a year before filming started to make the Hobbits' village.
Trivia: Not a mistake, but a wonderful in-joke. When Boromir is teaching Merry and Pippin to use their swords, you can hear him counting numbers as he delivers the blows to be parried. These numbers - "2, 1, 5" - are in fact the correct numbers for the system of parries used by the Society of American Fight Directors, and many stunt coordinators and fight masters worldwide. Boromir even matches the numbers to the correct locations. The numbering system is supposed to have been based on historic European fencing manuals, but if the folk of Middle-Earth knew it, it must have be a good deal older!
Trivia: When Frodo is leafing through Bilbo's Book in Rivendell, a page with dwarven runes is shown. The runes translate thus: "Stand by the grey stone when the thrush knocks, and the setting sun with the last light of Durin's Day will shine upon the keyhole." This is a reference to the map in "The Hobbit" and the runes tell of the secret entrance into The Lonely Mountain.
Trivia: The book of The Two Towers begins with the chapter, 'The Departure of Boromir', where he's found dead. The filmmakers decided to end the cinematic version of The Fellowship of the Ring with Boromir's death to provide a full arc for the character within the single film, whereas the book ends with his fate unresolved.
Trivia: When the four Hobbits fall down the hill, Merry says "That was just a detour, a shortcut." Sam asks "A shortcut to what?" and Pippin says "Mushrooms!" This is a reference to a chapter in The Fellowship of the Ring called "A Shortcut to Mushrooms." A number of chapters are referred to within the dialogue in various places. Others include: "A Long-expected Party," "At the Sign of the Prancing Pony," "A Journey in the Dark" and "The Breaking of the Fellowship." All of those chapter names except "A Shortcut to Mushrooms" and "A Long-expected Party" were also used by composer Howard Shore to name a piece on the LOTR soundtrack.
Trivia: In order to make people believe that Ian McKellen is taller than the four Hobbits, Peter Jackson and the production crew used a technique called forced perspective. This was achieved by placing McKellen consistently closer to the camera, and the eye is tricked into believing that McKellen towers over the Hobbits. A good example of this is when Frodo is riding with Gandalf in Gandalf's cart. Elijah Wood was sitting about 2 feet behind Ian McKellen.
Trivia: The costume department filled Bilbo's vest pockets with small stones so that the fabric would sag and look 'used' rather than new.
Trivia: In the Mines of Moria, in Balin's Tomb, there are a few shots where it only shows profiles of Aragorn's face. That's because Viggo Mortensen had gone surfing with the Hobbit actors, and his surfboard came up and hit his face. The right side of his face was swollen and he had a black eye. For about a week, the filming crew was only able to shoot his profile. (00:26:00)
Trivia: In the scene right after Bilbo leaves, Gandalf is sitting by the fire thinking to himself about how Bilbo acted when asked to give the Ring to Frodo, calling it his "precious" and all. While Gandalf is thinking, he mutters, "Riddles in the Dark." "Riddles in the Dark" is actually the name of the chapter in "The Hobbit" where Bilbo finds the Ring.
Trivia: When Aragorn parries the knife Lurtz throws at him, Viggo Mortensen successfully parried it on the first attempt. This is also done without special effects - the actor who played Lurtz' vision was so impaired that he could not see where he was supposed to throw the knife. If Mortensen had not parried it, he could have been seriously injured.