edit:
?link=http://... şeklinde kullanabilirsin.
<?php
$remote_file = $_GET["link"];
$new_width = 100;
$new_height = 100;
list($width, $height) = getimagesize($remote_file);
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($remote_file);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
header('Content-Type: image/jpeg');
imagejpeg($image_p, NULL, 100);
imagedestroy($image_p);
?>