Obtainning the public IP with EtherCard Library and ...

thats a good idea, is it possible to do so?

Im building this server so I can access thos via internt also, not just a lan server. But I have a DSL connection Dynamic IP . so I have to update my website with my server IP frequently. There are other ways such as DDNS and pachube.. But as this is a Uni project I need to do something by myself. so I had this little idea of obtaining my public ip qith arduino n update my web page with that some how.