There are some specials hidden on the Hetzner websites that they do not advertise on their front page.

It is for example possible to have a whole failover subnet and not just a single failover IP. They also offer SSD, USB stick, BBU for the RAID controller,  an extra Intel Gbit network card and much more. You can find the whole list at http://wiki.hetzner.de/index.php/Preisliste_Zusatzprodukte/en

Special offers and options to upgrade your existing Hetzner root server are listed at http://wiki.hetzner.de/index.php/Spezielle_Angebote/en