Add Virtual Host for OSX Mountain Lion

Update /etc/apache2/httpd.conf

NameVirtualHost 127.0.0.1

<VirtualHost 127.0.0.1>
DocumentRoot "website_root"
ServerName server_name
</VirtualHost>

<Directory "website_root">
Options FollowSymLinks
AllowOverride All
Order allow,deny
Allow from all
</Directory>

Update /etc/hosts

127.0.0.1 server_name