server {
        listen 80;
        server_name localhost;
        root /somewhere/;
        passenger_enabled on;

        error_page 400 http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#4xx_Client_Error;
        error_page 404 http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#4xx_Client_Error;
        error_page 500 http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#5xx_Client_Error;
}