How to share a USB port in a N/W? e.g.If a pen drive is plugged in sys.-1, how to access it from sys.-3?

Is it possible to share an USB port ? If so, how ? Consider in a network of 5 systems if i insert a Pen drive(or USB drive) in a port in system-1, then how to access it from system-3 ?. If anybody know the answer, then do pls. reply me.