In 1961 Disney made a movie about two twin girls who, separated at birth, find each other and switch places. After switching they go to homes in distant locations across the country. They make a few communications with each other. Disney remade this movie a few years ago. I observed the telephone usage. Actually, considering the time, it didn't change that much.
In the first movie, the girl was using a Princess phone, which was still rare in 1961. The dial light was very bright and I wonder if the phone was a model, not a real telephone set. The girl at the other end used a black 500 set. The family was wealthy and had colored phones all over the house, again, a rarity in those days. (Color phones cost extra.)
In placing calls, she dialed operator. In answering the call, the other girl heard the operator announce the call. No concern was expressed about the cost of a long distance call.
One girl had to reach the other urgently, so she sent a Western Union telegram. The other girl's family was quite surprised at the girl receiving a telegram, and with a cryptic message on it. The girl explained it was from a friend at camp and in code. She later snuck to use the phone late at night. Her grandfather happened to catch her and found out about the switch.
Now as to the second movie, the telephone usage was roughly the same, except there was no operator. This time one girl lived in Calif, the other was in London. No mention made about placing the call.
Instead of a telegram with the urgent message, a fax was sent. The girl had to sneak to the fax machine to get it without anyone seeing her. Her next call was at a pay phone (calling overseas not explained), and her grandfather caught her.
Ironically, a pay phone was used in the later movie in an era when pay phones were declining.
In the remake, I don't recall the girls having cell phones.
Overall, there wasn't much telephone use in the movies. The movie's plot was originally from a German short story which may have been even older and from a time when the telephone didn't figure as much.
One other observation: The original movie contained some physical contact, that is, when the girl got too fresh with her parents they slapped her (this happened twice). The remake had none of that. The parents in the remake, particularly the father, seemed to be a much "softer" character. This is a reflection of the times, in 1961, if a kid was excessively ornery or disrespectful he/she would get slapped or a smack on the behind. In 2000 parenting styles are completely different. Indeed, seeing a child being slapped startled me; I forgot how social mores have changed. In 1960 human interaction contained more physical contact or threat of physical contact and it was socially acceptable. Also, the father in 1961 carried a prominent rifle on his ranch, no such item in 2000.