Oh and NAS, many of them are slow and even the fastest is NOT as fast as server, at least from what I've read.
If you've got an old computer, or old part laying around from upgrades that you can cobble together to make a computer, consider setting up a file server and plugging it into your network. Any Windows Computers can be set up to be a file server, for a long time I had an old Windows 98 computer running as my file server. I experimented with free Linux Server software, it was OK, but I just didn't have time or the inclination to learn Linux well enough for it to be practicle.
I ran Beta's of Windows Home Server (WHS), that was nice, but the Beta ran out. I'm currently running the Beta's of WHS v2 (Vail), you need a 64bit processor for the later version, I had to buy a cheap mobo and processor to upgrade to use the Beta. I love it, but MS just got rid of the drive extender feature, that everyone loved. It combined all your drives into one JBOD array, and you had an option to mirror every file and it would distribute the mirrors amoungst the drives, so you never lose a file to a bad drive. BUT, of course mirroring the files, like a raid 1 drive, takes up twice as much space.
WHS, MS is only half-hearted about it, they limit it to OEM's, so unless you buy one of the hardware WHS from a couple of big computer manufacturers out there, you're stuck with buying an OEM disc online or downloading and using a BETA version, which is a lmited amount of time of use.
WHS with a Gigabit Network, file transfers are blazing fast, I watch movies from the server, I install software from the server, etc.