When discussing his grand plans, Lex Luthor makes a throw-away line and names a country to be blown up apparently at random. Not quite so random - it was changed in each country of release.

To get the muscular build required to play Superman Christopher Reeve went on a training regime supervised by David Prowse who played Darth Vader in the first Star Wars trilogy.

When young Lois Lane and her parents are riding in the railroad train and she sees Clark running past them on the road, her mother is played by Noel Neill, who played Lois on the 1950's TV series, and her father is played by Kirk Alyn, who played Superman in the 1948 movie.

If you look very closely when Superman is floating in Lex Luther's swimming pool, you'll notice a small floatation device placed under his cape to keep his head above the water. That's because Superman boots weighed a whole lot after they became filled with water. The floatation device made it easier for Clark Kent to swim during that scene.

Not really a mistake, but I found it interesting that when Clark Kent turns into Superman he takes the time to comb his hair to the other side.

The famous (or infamous) New York City blackout of 1977 occurred during location shooting for "Superman." According to director Richard Donner, cinematographer Geoffrey Unsworth mistakenly believed he had caused the blackout by plugging in a spotlight to a lamppost while filming.

According to the commentary, the 4 minute helicopter crash scene took nearly 12 months to film. Director Richard Donner wanted perfection.

Something for Cheers fans: John Ratzenberger (Cliff) is an extra, playing a control booth worker.