If you don't want a site indexed by the search engines, just put a robots.txt file in your root directory that looks like this:
Code:
User-agent: *
Disallow: /
User-agent: Phpdig
Disallow:
The last two statements are there because you don't want to chase away the phpdig spider.
Of course, if you don't want any human to see the link, that's a whole other story.