The web page Officer Russell tries to access after noticing a lack in communications is ogdenmarshsheriff.com--an actual active site specially made for this movie and with Sheriff David's (Timothy Olyphant) picture as active sheriff. By logging in (Username: ddutten, Password: judy) you can listen to recorded phone calls in relation to the movie.
The film opens with the song "We'll Meet Again," as performed by Johnny Cash. The song is from the same album that provided "The Man Comes Around," which opened another remake of a George A. Romero film, Dawn of the Dead (2004). The album is "American IV", the last full album Cash released before his death. "The Man Comes Around" and "We'll Meet Again" are the opening and closing tracks, respectively.
When the sheriff discovers the military plane, a satellite records his location at 40.851216 and -94.548340. These coordinates do in fact point to Iowa, but to farmland and not to the marshes as depicted. The town of Lenox, population 1401, is the closest real town to these coordinates.
The 12th -ilm released in select D BOX-enabled cinemas, located in the US and Canada. In D-BOX's words, the motion control technology "adds to the movie's plot and underlying themes of fear, terror and explosive action by offering realistic sensations during most of the film's action scenes."
The trivia item below may give away important plot points.
During the closing credits there is a news broadcast about people who reported seeing a large fireball in the area of Ogden Marsh. The newscaster is Bruce Aune, a real-life newscaster for KCRG Channel 9, the local ABC affiliate in Cedar Rapids, IA. The actual logo of KCRG is also shown during the broadcast.