#Buffalo Network Attachable Storage
As discussed you're free to have this Buffalo HS-DH500GL 500GB NAS to use a media server, etc. I believe it can be used in conjunction with external USB drive, but I've never really tried ... It is now more than 6 years old, so if it doesn't work as a media server, don't try too hard :)
It's on DHCP - If you can't find the IP assigned through your router, or just for kicks, download the NAS Navigator, which will find it on your network and also allow you to set a fixed IP, etc. if needed.
http://www.buffalotech.com/support-and-downloads/download/nasnavi-281.zip
Once you get the IP, the below should suffice.