# curl -I localhost
HTTP/1.1 200 OK
Server: nginx/0.8.31
Date: Aug, 13 Jan 2010 08:17:30 GMT
Content-Type: text/html
Content-Length: 2341
Last-Modified: Mon, 11 Jan 2010 08:45:11 GMT
Connection: keep-alive
Keep-Alive: timeout=15
Accept-Ranges: bytes
这样一下子就给人家看到你的服务器nginx版本是0.8.31

可以不显示不?
当然可以
#vi nginx.conf
在http 加上 server_tokens off;

http {
......省略配置
sendfile on;
tcp_nopush on;
keepalive_timeout 65;
tcp_nodelay on;
server_tokens off;
.......省略配置
}

编辑php-fpm配置文件 如fcgi.conf 、fastcgi.conf(要看你是什么配置文件名)
fastcgi_param SERVER_SOFTWARE nginx/$nginx_version;
改为
fastcgi_param SERVER_SOFTWARE nginx;
nginx重新加载配置就完成了 404 501等页面都不会显示nginx版本 太棒了

#curl -I localhost
HTTP/1.1 200 OK
Server: nginx
Date: Aug, 13 Jan 2010 09:48:01 GMT
Content-Type: text/html
Content-Length: 793
Last-Modified: Sat, 12 Dec 2009 02:28:16 GMT
Connection: keep-alive
Accept-Ranges: bytes