The rather odd-looking pistol that Inman is carrying before he is captured by Confederate soldiers is an 1860 Beauregard LeMat, which was a favored weapon of many Confederate cavalrymen, as it held nine shots as well as a lower barrel with a .28-gauge shotgun load. This was the type of pistol carried by Confederate General JEB Stuart.
The names of Sally Swanger's sons, "Acton" and "Ellis", are also the names that Anne Brontë and Emily Brontë used as pseudonyms to hide their genders when marketing their novels. They used "Acton Bell" and "Ellis Bell" and their sister Charlotte Brontë used the name "Currer Bell".
When Inman heads off to war there is a banner, "Old Rip's Awake! Watch out Yankees!" posted on the Cold Mountain General Store. This is in reference to North Carolina being known as "The Rip Van Winkle" state.
The book was written similarly to how the film was shot. In the book alternating chapters are spent following Inman's journey and Ruby & Ada's plight; the movie does the same, switching back and forth between two compelling storylines, each significant stories in their own right.
At one point in his journey, Inman asks a local if he's near the Cape Fear River. Cape Fear is adjacent to the coastal city of Wilmington, and the Cape Fear River runs south through Wilmington. The region is the namesake of the movies Cape Fear (1962) and Cape Fear (1991).
One of countless movies to more or less follow Homer's epic tale "The Odyssey", about a man being far removed but on a journey back to home against seemingly impossible odds. In recent years "Oh Brother, Where Art Thou" (2000) is another example.
At :26 when Inman and Ada enter the church, they do so to wrangle a bird in the dove family, the "bird of peace and love". This obviously representing or foreshadowing the budding relationship between the two.
The trivia items below may give away important plot points.
In the original script, Inman stays with Sara to help clean up after the encounter with the Union soldiers, but Sara's baby dies and a grief-stricken Sara shoots herself. This is one of the deleted scenes on the DVD.
One of the DVD deleted scenes shows Inman finally arriving back at Cold Mountain only to find that Georgia is the only one at the house. Georgia tells Inman that Ada and Ruby are a long ways off in the mountains, and Inman sets off to find them.