I have read a bit about "Network-Attached Storage" (NAS). I knew the term generally but was not sure what the exact definition was. I should have known better. Of course the term has little meaning.
Ok. So in general what I want is a NAS.
The other thing I found out was that "while I was looking everywhere else" D-Link snuck a fast ball past me, and I already have one! Actually, what happened was that a few months ago I decided to upgrade my network to a "DIR-655" which supports Gigabit Ethernet (NOTE: In my previous post I was saying "Gigabyte" Ethernet. Well, yeah, I would really love "Gigabyte" Ethernet, but practically speaking I would not be able to afford that for at least a couple of more years.). It also supports WiFi "Draft N". And it also had a USB connector which was almost completely useless because it was only supporting a single function as a conduit for setup data. That is to say, you plugged a Flash device into your computer and downloaded some setup data and plugged it into the Router and the Router would set everything up for you. Even people who have all the hardware and software to use this feature never bothered to use it.
Anyway, I found out that just recently (weeks ago?) D-Link released a firmware upgrade that includes using that USB port as either a data drive port (for hard drive or Flash device), or as a Printer port (with support for FAX and Scanner on multifunction devices).
At this point, there is only Windows support. At least that is all I know about. But I expect the Linux distros will eventually support it too.
The performance of this setup will probably not be as good as a true separate NAS box (mainly because the processor in the Router is not really even powerful enough to cover all the data moving possibilities already in use), but at the least, I should be able to gain some experience with it so I will know what I want to buy later.