[cd34]

actually, that won't work completely.

You have to take into account that google uses images.google.com.

Then you have to consider that they also use images.google.ca, and images.google.fr, etc.

Then you decide, hey, I'll just add 'google' to the list, and fusker starts using google.fusker.com or fusker.com?google.php.

Its a never ending battle.

Also, to my knowledge, I haven't seen any google sites with Googlebot-Image in the hostname -- that looks more like a UserAgent. Since their robots don't send referrers, and that doesn't look like something that would be in the referrer, I think that line might not be needed. I could be wrong. Happens a lot.