Best How To :

The easiest way to do it in PHP is to use file_get_contents() (fopen() also works), if the HTTP stream wrapper is enabled on your server:

<?php
$postUrls = array(
    'http://my.site.here/post1',
    'http://my.site.here/post2',
    'http://my.site.here/post3',
    'http://my.site.here/post4',
    'http://my.site.here/post5',
);

foreach ($postUrls as $url) {
    // Get the post as an user will do it
    $text = file_get_contents();
    // Here you can check if the request was successful
    // For example, use strpos() or regex to find a piece of text you expect
    // to find in the post

    // Replace 'copyright bla, bla, bla' with a piece of text you display
    // in the footer of your site
    if (strpos($text, 'copyright bla, bla, bla') === FALSE) {
        echo('Retrieval of '.$url." failed.\n");
    }
}

If file_get_contents() fails to open the URLs on your server (some ISP restrict this behaviour) you can try to use curl:

function curl_get_contents($url)
{
    $ch = curl_init($url);
    curl_setopt_array($ch, array(
        CURLOPT_CONNECTTIMEOUT => 30,        // timeout in seconds
        CURLOPT_RETURNTRANSFER => TRUE,      // tell curl to return the page content instead of just TRUE/FALSE
    ));

    $text = curl_exec($ch);
    curl_close($ch);

    return $text;  
}

Then use the function curl_get_contents() listed above instead of file_get_contents().