If you want just to show your site's url just use
Code:
echo $_SERVER['SERVER_NAME'];
but I'm not sure if I got you right: if you want to pull content from other site into your footer
PHP Code:
<?php include('http://www.yoursite.com/site.php');?>
but if your site is not allowing remote includes you should add this to the .htaccess
PHP Code:
allow_url_include 1
or, if you prefer
PHP Code:
allow_url_include on
if that is prohibited by your hosting provider, you should use cURL
(you can contact me and I can write that for you)