Presuming you're using PHP, do something like this in your script:
if(!empty($_GET['get_page'])) {
if(!filter_var($_GET['get_page'], FILTER_VALIDATE_URL)) {
// Not a URL.
exit;
}
$page = file_get_contents($_GET['get_page']);
if($page === false) {
die('Page request filed.');
}
echo file_get_contents($_GET['get_page']);
}
Make sure you have set "allow_url_fopen" to 1 in your PHP config.
Then just call "whatever_page_you_put_the_code_in.php?get_page=http://blah.com/blah.php" instead of the website.
Just note that some websites forbid visitors who have no UA from accessing the site, and this can be easily abused as it is pretty much a proxy.
Might not work, but it's worth a try.