In many scenes throughout the movie, Billy Crystal is seen wearing either a sweatshirt or a t-shirt from New York University. Billy Crystal graduated from New York University with a Bachelor of Fine Arts in 1970.
Because the film is about extras, many of the extras are listed in the ending credits. Something that is rarely done.
Sean Connery: Abe (Alan King) introduces Abbie (Billy Crystal) to Sir Sean Connery, who happens to walk by dressed as Lieutenant Colonel Alan Caldwell from The Presidio (1988). Connery was in costume for filming and did this appearance in between takes.