apache virtual host

1.single machine -- running multiple web server simulation
follow
http://www.debuntu.org/2006/02/22/7-virtual-hosting-using-apache-2

2.directory access
http://www.cyberciti.biz/faq/apache-restrict-access-based-on-ip-address-to-selected-directories/
http://httpd.apache.org/docs/1.3/howto/auth.html#basic