In the Duke Nukem's "Titty City" chapter, there are two ATM machines, one near the bar and one near the slot machines in the game room. Go up to one and use it it will say "card read error", press action again and it will say "Feed me a stray cat" -- it works on both of them but it won't repeat again. This is a reference to the scene in American Psycho when Patrick Bateman tries to use an ATM machine and it appears to him to say "Feed me a stray cat" and he tries to before a woman yells at him and he runs off.