Google up the GMFPSU22W6 which I picked up two of for under 25 each.
Ok, now I have USB drives on my Ethernet and network. But the speed over wifi is abysmal and barely tolerable wired. Here's partly why ->USB 2.0 sprints (?) along at 480 million bits per second and your common Ethernet is 100 million bits per second (Mbps). Ethernet is FULL DUPLEX and when we move to WIFI that's shared bandwidth at 54 Mbps on a good day.
My GMFPSU22W6's do fine as print servers but the USB drives are now back on the machines via USB when I need them.
Many times I come across people that would like to add networked backup to their home network but don't want to buy a new router with a USB port. If there are no desktop computers in the home, they won't want to tether a drive to one laptop only for the drive to not be available to others should that laptop be moved. Is there an adapter that will allow an external USB hard drive to connect to an ethernet port on a router that can then be shared?