Dream Job: To Cast "Those People" in Movies

Have you ever seen a person in a movie and thought to yourself, "how in the world did they find that guy?"  Like the other day I was watching "Lost in Translation" and that scene when Bill Murray is in the hospital waiting on Scarlett Johansson and he has that funny conversation with that old Japanese lady?   How did someone find that old Japanese lady?

Or how about the movie "Happy Gilmore?"  Remember that super weird looking caddy he has towards the beginning of the movie?  It's a kid with weird curly blond hair who kind of looks albino and frankly psychotic.  Who the hell found that guy?