Many of the Cell-Block Tango singers were in the Chicago revival along with Taye Diggs
Billy Flynn calling Amos Andy throughout the movie is in reference to the radio show "Amos and Andy"
Madonna, Goldie Hawn, Kathy Bates, Rosie O'Donald, Nicole Kidman, Gwenith Paltrow, Careron Diaz, and Brittany Spears were all considered for roles (Scarey huh?)