The invite module has a functionality similar to the referrals module. Using invitations sent by a user or a referral link, a visitor can create an account in the site. The invite module has one more option too. It allows the administrator to lock user registrations to be invitations-only. And it works quite well! The problem is that this invitations-only doesn't include referrals since it is a completely different module. As a result, I created a module to lock user registrations to be invitations-or-referrals-only. You can download the module from here or you can visit the drupal issue queue where I also posted the module.
The drupal_http_request() function supports connections using a proxy. You can configure a global proxy to use for all drupal_http_request() callbacks from the settings.php file of your website/installation by filling the following lines with the proper information:For those of you preferring a UI, then HTTP proxy module is for you.But what if you only want to use a proxy in some cases; like a custom module? In that case you will need the following function(modify accordingly):Now all you have to do is Call <?php _MYMODULE_change_proxy(); ?>.Do your drupal_http_request() calls.Call <?php _MYMODULE_change_proxy(TRUE); ?> to reset your previous settings.