The last line of Superman IV: The Quest for Peace (1987) is Superman saying to Luthor, "See you in twenty." That scene was filmed in 1986. Coincidentally, twenty years later, this film was released.
In interviews, Kal Penn revealed he originally had a much greater role. It would have been revealed that his character was a disgraced former Daily Planet science reporter who was bribed by Lex Luthor to plant false evidence of Krypton's possible survival, thus inspiring Superman to leave Earth and explore Krypton's ruins.
Workers constructed seven kilometers (4.35 miles) of road, and planted fifteen hectares (37.065 acres) of corn to recreate the Kent farm. This is especially a difficult task, in that the farm was created during a seven-year drought in Australia.
When Bryan Singer became interested in possibly hiring Brandon Routh, he arranged for them to meet in a coffee shop. When they met at their table, Routh stumbled and spilled hot coffee all over the table. Although he panicked, thinking he had just lost the part, Singer laughed and said it actually helped him get the part. The incident convinced Singer that Routh could pull off the clumsy, bumbling Clark Kent.
(at around 26 mins) Jimmy Olsen from Adventures of Superman (1952) appears as a bartender who serves to Clark and Jimmy.
(at around 5 mins) as Gertrude Vanderworth. She played Lois Lane in Superman (1948), the 1950s TV series Atom Man vs. Superman (1950), and Adventures of Superman (1952) and played Lois' mother Ellen in Superman (1978).
(at around 57 mins) the two writers of the screenplay make an appearance as school kids making notes as Lex Luthor arrives to steal the meteorite and shoos them away.
(at around 1h 40 mins) Production designer: one of the journalists of Daily Planet, who first notices the tremor at the building.