Parrallel
The first and final scene for Lex Luthor are actually parallels of one another. During the “Pilot” episode, Lex is seen stepping out of a car and turning to the camera. His final scene in “Finale Part II” shows Lex turning to face the cameras just as he did in his first ever scene 10 seasons before.
Lana Lang
Allison Mack learned about casting for Smallville from the casting director Dee Dee Bradley. Originally Mack thought about trying out for the part of Lana Lang. Instead she chose to audition twice for the part of Chloe Sullivan.