I have several hard drives taking up space, I'm looking for a way to turn 1 of them into a network storage device that I can just plug into my router and access from my other PC's.
I think this is what you are looking for, but you will need to buy a usb hardrive caddy. Or you could share the drive over the network (is it allready inside a pc?), the disadvantage with this is that this computer must be turned on to use it!
actually I would prefer to get some sort of NAS appliance but add the hard drives myself instead of buy one with the storage space included.
you can buy fully functional network storage (incl disc drives) here (allso includes stuff ror attaching usb drives) ps, thats a uk site