This code can be used to get Google page Rank for a website…

/*Google PageRank interface
providing functions for getting and displaying Google PR's. Checksum functions are based
on public domain code created by Alex Stapleton, Andy Doctorow, Tarakan, Bill Zeller, and
Vijay "Cyberax" Bhatter. Many thanks!*/
<?php
      	function StrToNum($Str, $Check, $Magic) {
    $Int32Unit = 4294967296;  // 2^32

    $length = strlen($Str);
    for ($i = 0; $i < $length; $i++) {
        $Check *= $Magic;
        //If the float is beyond the boundaries of integer (usually +/- 2.15e+9 = 2^31),
        //  the result of converting to integer is undefined
        //  refer to http://www.php.net/manual/en/language.types.integer.php
        if ($Check >= $Int32Unit) {
            $Check = ($Check - $Int32Unit * (int) ($Check / $Int32Unit));
            //if the check less than -2^31
            $Check = ($Check < -2147483648) ? ($Check + $Int32Unit) : $Check;
        }
        $Check += ord($Str{$i});
    }
    return $Check;
}
function HashURL($String) {
    $Check1 = StrToNum($String, 0x1505, 0x21);
    $Check2 = StrToNum($String, 0, 0x1003F);

    $Check1 >>= 2;
    $Check1 = (($Check1 >> 4) & 0x3FFFFC0 ) | ($Check1 & 0x3F);
    $Check1 = (($Check1 >> 4) & 0x3FFC00 ) | ($Check1 & 0x3FF);
    $Check1 = (($Check1 >> 4) & 0x3C000 ) | ($Check1 & 0x3FFF);    

    $T1 = (((($Check1 & 0x3C0) << 4) | ($Check1 & 0x3C)) <<2 ) | ($Check2 & 0xF0F );
    $T2 = (((($Check1 & 0xFFFFC000) << 4) | ($Check1 & 0x3C00)) << 0xA) | ($Check2 & 0xF0F0000 );

    return ($T1 | $T2);
}

function CheckHash($Hashnum) {
    $CheckByte = 0;
    $Flag = 0;

    $HashStr = sprintf('%u', $Hashnum) ;
    $length = strlen($HashStr);

    for ($i = $length - 1;  $i >= 0;  $i --) {
        $Re = $HashStr{$i};
        if (1 === ($Flag % 2)) {
            $Re += $Re;
            $Re = (int)($Re / 10) + ($Re % 10);
        }
        $CheckByte += $Re;
        $Flag ++;
    }

    $CheckByte %= 10;
    if (0 !== $CheckByte) {
        $CheckByte = 10 - $CheckByte;
        if (1 === ($Flag % 2) ) {
            if (1 === ($CheckByte % 2)) {
                $CheckByte += 9;
            }
            $CheckByte >>= 1;
        }
    }

    return '7'.$CheckByte.$HashStr;
}
function getch($url) { return CheckHash(HashURL($url)); }
function getpr($url) {
$googlehost='toolbarqueries.google.com';
$googleua='Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5';
    $ch = getch($url);
	$fp = fsockopen($googlehost, 80, $errno, $errstr, 30);
    if ($fp) {
       $out = "GET /search?client=navclient-auto&ch=$ch&features=Rank&q=info:$url HTTP/1.1\r\n";
       $out .= "User-Agent: $googleua\r\n";
       $out .= "Host: $googlehost\r\n";
       $out .= "Connection: Close\r\n\r\n";
           fwrite($fp, $out);
         while (!feof($fp)) {
            $data = fgets($fp, 128);
            //echo $data;
            $pos = strpos($data, "Rank_");
            if($pos === false){} else{
                $pr=substr($data, $pos + 9);
                $pr=trim($pr);
                $pr=str_replace("\n",'',$pr);
                return $pr;
		//echo $pr;
            }
       }
       //else { echo "$errstr ($errno)<br />\n"; } //debug only
       fclose($fp);
    }
}
?>
//*********************************** Usage ****************************

echo getpr('samplephpcodes.com');
echo '<a href="http://www.samplephpcodes.com">sample php codes</a>';