Накидал тут такой вариант...
private function sBot(){
if (stristr($_SERVER['HTTP_USER_AGENT'], 'Yandex')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'YandexBot')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Yandex')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'YandexDirect')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Googlebot')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Google')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Mediapartners-Google')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Slurp')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'WebCrawler')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'ZyBorg')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'scooter')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'StackRambler')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Aport')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'lycos')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'Yahoo')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'WebAlta')){ $sBot = true; ;}
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'yahoo')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'msnbot')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'ia_archiver')){ $sBot = true; }
else if (stristr($_SERVER['HTTP_USER_AGENT'], 'FAST')){ $sBot = true; }
else $sBot = false;
return $sBot;
}
Может есть тропа по легче?