After the article explaining the method I coded this easy to use PHP script that does the trick for you and also caches the results for further use. This way your site will not be slowed down at all.

Ever wondered if the googlebot user agent that is just crawling your site is really googlebot? Search engines implemented an easy way to verify them using a round DNS query on both host and IP address.
Saving bandwidth and protecting sensitive information is piece of cake.
Check out two see cute yet somehow freaky videos with cats and dogs!
The Universe seems to have a void space of 1 billion light years across. That space seems to contain the proverbial nothing ... and by nothing it really means nothing.

I long awaited for this moment and it finally arrived. They've announced the 3rd part of one of my favourite movies Resident Evil 3 - Extinction.
Having the bad habbit of doing small but important changes live on my site I managed to issue robots the error code that gives one the chills: 403 [Forbidden Access] . The official specifications say when you send a 403 you say : resource exists but not for you! So the robots should stop visiting it.
Learn what really happens.