USB hub with built-in ethernet?

Does this exist?

I want a device which lets me plug multiple hard drives into it so it can act like a hub, but which also allows me to access any of the drives over the network when I want to. A NAS wouldn't work because I want the ability to remove the drive without having to put it in another enclosure etc. I'd rather just swap it and go.

I drew a picture:


So basically...it's like a usb hub, except you can choose whether you want to use usb to access everything connected to it OR you can choose to use ethernet.

Edit: Would this work http://www.amazon.com/Buffalo-Technology-DriveStation-TurboUSB-HD-CE500LU2/dp/B001IG6VI0 if I have up the ability to have multiple drievs and just put everything on that?

 

Ahh, does the LaCie allow me to connect the usb drive directly to something else as well? Like let's say a device that isn't network-enabled also needs access to the drive and has a usb port...can that still work here? My understanding is that the USB port on NAS drives is for you add an additional hard drive, not to use the drive as if it were a regular USB drive.