You can't do it directly, but there are a few devices that will let you do this that put USB storage or printers on your network.
One of the best ones that I have seen is the Cirago NUS2000. It has four USB ports and can have both storage devices and printers hooked up to it. It uses a wired ethernet cable to plug into your router or network switch. It is available for $60 to $70. There is a review of it at:
http://www.pcmag.com/article2/0,2817,2391004,00.asp
The only real drawback is that it is slow. You can find the actual device at many resellers, including Amazon and NewEgg.
Here is a shopping link:
http://www.amazon.com/Cirago-International-NUS2000-CiragoLink-Network/dp/B005C31H34/
If you want something less expensive that...