This is a great extension but the configuration is difficult and tedious. You need to install Ioncube on your server for the component to work and with only a handfull of tutorials on installing Ioncube, its not easy. Unless your a pro. I spent almost a whole day on this so if anyone needs help you can contact me. Overall if your running a social networking site download this extension, with the ability for users to import their contacts from e-mail and social networking sites, it has the potential to increase your website traffic.
As of June 2011, Ioncube is no longer required :)