I have ordered my NAS solution

A NAS is really the vital component of any home network. Basically it's a place to store all of your files: documents, pictures and possibly audio and video. But a NAS is not limited to that, as recently they started to look more like servers. They can be configured as Web ot FTP servers or, more interestingly, as UPnP servers which basically means that they can serve media content to all the media clients around your network: PCs but also Media Adapters for Audio and Video.
I already have a Netgear MP101 that I like a lot to listen to my MP3 music at home but the problem is that it always require a switched-on PC to work. It doesn't really make sense when all you are using of it is basically its Hard Disk.
That's exactly where a NAS fits into the picture: they are cheap (compared to a PC) and efficient. In my case I plan to use a Linksys NSLU2 a small and neat diskless unit with two USB port that you can connet to external storage. I'm also going to buy a Buffalo HD-HB250U2-1 USB 2.0 Drivestation 250 Gb to have enough space to store my music and a lot of videos in the future (but that's a future project). All of this is only around £130.
Unfrtunately today setting up a NAS with extended functionality still requires a little bit of hacking that will probably keep me busy in the next weeks (see http://www.nslu2-linux.org/). my plan is initially to install Twonkyvision as UPnP media server.