Prova questo
codice:
<?php
$host = "myip.dk";
$fp = fsockopen ($host, 80, $errno, $errstr, 30);
if (!$fp) {
   echo "$errstr ($errno)
\n";
} 
else {
  fputs ($fp, "GET / HTTP/1.0\r\nHost: ".$host."\r\n\r\n");
  $buffer = "";
  while (!feof($fp)) {
    $buffer .= fgets ($fp,128);
  }
  fclose ($fp);
}
preg_match_all("/<title>.*?<\/title>/i", $buffer, $ris);
echo (str_replace(array("<title>", "</title>", "Your IP: "), "", $ris[0][0]));
?>