If you need it portable, as others have mentioned, I suggest the "SLUG" (Linksys NSLU2). You can easily flash the firmware and run linux on the system.
Before I decided to build out a linux server just for the NAS, I was running one of these little puppies and was quite impressed. It handled all of my file sharing needs, backup needs, and I had an ssh server running which allowed me to do ssh tunneling instead of poking holes in my firewall for remote access to my home devices. I also was able to run ctorrent to remotely manage torrent downloads.
I still think the best idea is to just build up a computer from newegg and have a dedicated linux machine as your NAS.
Before I decided to build out a linux server just for the NAS, I was running one of these little puppies and was quite impressed. It handled all of my file sharing needs, backup needs, and I had an ssh server running which allowed me to do ssh tunneling instead of poking holes in my firewall for remote access to my home devices. I also was able to run ctorrent to remotely manage torrent downloads.
I still think the best idea is to just build up a computer from newegg and have a dedicated linux machine as your NAS.