Amazon have great deals on Drobo units at the moment, I recently bought one with the NAS add-on.

Amazon UK Drobo Unit

The great thing about the NAS (Network-attached storage) add-on is that you can install Apps (it’s Linux based). Such as: FTP server, iTunes server, Xbox360 server etc. Which I’ve done, so all music and movies live on the Drobo and are wirelessly streamed to the Mac Mini (HTPC), Xbox360, Imac etc.

Drobo Apps