OS X has a very cool feature built into to its resolver: /etc/resolver. It allows you to specify different DNS servers for different domains. After creating the /etc/resolver directory, I can create a /etc/resolver/erdelynet.com file with “nameserver 192.168.25.10″ in it. Now, my Mac will use 192.168.25.10 for resolving erdelynet.com and whatever my ISP assigned me for everythying else.
via erdelynet.com