How to integrate GetResponse with Magento register page

so on our register page for new customers, we have a check box for people that want to receive our newsletter.

You can see here: http://screencast.com/t/B2PUrelvnm1X

Only problem is that we use GetResponse for our newsletter. Is there anyway to make it so that if a user checks that checkbox, they will be added to GetResponse rather than to the back-end of Magento's built in newsletter system?

Up til now, we've just been manually importing them over, but it would be nice to have this streamlined / automated.

Thanks!

You can observe the event <customer_register_success>.
See here how to create an observer..

Now, your method that observes the event should look something like this:

public function checksubscription($observer) {
    $customer = $observer->getCustomer();
    if ($customer->getIsSubscribed()) {
        //if the customer subscribed to the newseltter send it to GetResponse
        //sorry but I don't know how the GetResponse API works.
    }
}