Was looking at some routers in the past couple days and saw something else that may help. On some routers they have a USB port on the back so you can hook up an external HD or printer so all the PCs/devices on the network can use it. I am not sure if you could access it from more then 1 device at a time though. Maybe someone else on here knows.
Of course this would only work if all the devices connect to your router (assuming of course that you have one). The router you have may have a USB port and you might not have realized it. Hope this helps!