I have somewhat of a staging server on the public internet running copies of the production code for a few websites. I\'d really not like it if the staging sites get indexed. <
To truly stop pages from being indexed, you'll need to hide the sites behind HTTP auth. You can do this in your global Apache config and use a simple .htpasswd file.
Only downside to this is you now have to type in a username/password the first time you browse to any pages on the staging server.