The music underscoring the girls' march to the "isolation cabin" was originally used in The Great Escape (1963), scored by Elmer Bernstein.
The name Meredith Blake is a reference to a male character in "Five Little Pigs", a story written by Agatha Christie. An adaption of that story was produced for the TV series "Agatha Christie: Poirot" (1989).
# # To find the actress who would play Hallie and Annie, an exhaustive casting search was conducted in Boston, Chicago, Minneapolis, Atlanta, Miami, Vancouver, Toronto, and London, with open calls in New York and Los Angeles. Eventually 11-year-old Long Island native Lindsay Lohan was given the role.
In casting the dual role of twins Hallie and Annie, director Nancy Meyers kept saying, "I'm looking for a little Diane Keaton... Diane is so alive on screen and that's what I wanted from the actress in these parts."
When this movie was shown on Disney Channel, the scenes where Hallie pierces Annie's ears, when Annie (Hallie) takes a sip of the wine, and when Annie rides the plane to London are cut.
Camp Walden is based on an existing camp for Girls Denmark Maine. There is no Isolation Cabin.
The reaction of Nick Parker (Dennis Quaid's character) reaction to seeing Elizabeth (Natasha Richardson's character) for the first time in 11 years is identical to James Garner's character's reaction in Move Over, Darling (1963) upon seeing his missing wife after 5 years. In both films, the man is on an elevator with his current partner and leans over in disbelief as the door closes. James Garner's character in Move Over, Darling (1963) is also named Nick. James Garner actually copied the move in the elevator from Cary Grant who did the same thing in the movie My Favorite Wife (1940). When Cary Grant entered the elevator with his new bride Gail Patrick he was shocked to see his first wife Irene Dunne who after seven years had been declared missing at sea and presumed dead that very morning. Move Over Darling is a remake of My Favorite Wife.
# # The name of the hotel, The Stafford, is a reference to the name of a boy in the original The Parent Trap (1961). He is the boy Hayley Mills' character, Susan, is talking to at the camp dance.
We learn that Camp Walden is in Maine from seeing the State Flag from Maine as it is going up in the morning and also when it comes down in the rain storm. Also in the scene where Hallie and friends are rigging Annie's room, you see them using vegetable oil from Hannaford Bros, and Great Lost Bear chocolate sauce. Both are local Maine brands.
Annie makes a call to 'Mildred Plotka', a reference to the 1964 movie.
From the opening of the film we find out that the parents were married on 8 January 1986. Nicholas Parker was 24 and Elizabeth James was 23. Elizabeth's occupation is listed as artist, while Nick's is listed as Viticulturist.
The scene where Annie and Hallie are lying in bed and the camera pans from the moon, to the parents' picture, to the twins took six hours to get it right. Lindsay Lohan' had to change from Annie to Hallie, and back all the time.
The man who weds the parents at the beginning is played by Director of Photography, Dean Cundey.
# # Michelle Trachtenberg was considered for the role(s) of the twins. Coincidentally, the actress's birthday falls on 11th October, the same day as Hallie and Annie's in the film.
Writer and director Nancy Meyers handpicked Lindsay Lohan to play the dual role of the twins in the film, and phoned the Lohan household herself to inform the actress that she had landed the part.