What cell phone?

Rating: 9/10 (23 April 2013)

At the early stages of this film, when Andy arrived at the prison in a bus full of other prisoners, one of the guards told the new arrivals to discard their cell phones. Did I hear this incorrectly? Anyone knows that cell phones were not invented anywhere near 1947.
As for the film itself, I rarely score a '9' and the only '10' was 'Montenegro,' an American/Swedish co-production, black comedy made in the mid-80's. Tim Robbins and Morgan Freeman, as well as the warden (Frank Dunton) were superlative and the script was so good, one might think the story was based upon fact, whereas it is fictional.
A Yale (or was it Harvard?)law school study revealed that 7% of incarcerated inmates are innocent. One prominent attorney said that was an 'acceptable' percentile. I don't want him as my defense attorney.
I liked the ending. It doesn't leave the viewer hanging. While sanding his boat in working clothes, I'm sure Andy lived in a mansion above the Pacific Ocean. $377,000 was a lot of money in 1966.