A sharing hub is a very short lived device(saw it once at walmart and for a short time on tigerdirect) that was made with 2,4 or 7 usb ports that allows 2 computers to share usb devices.
Each port is switched allow you to lets say swap a mouse, keyboard, memory card reader, hard drive or any usb device from computer A to B without effecting other devices connected.
My first one was just like this, but it was sold at walmart. I actually picked it up on impulse. It actually is used all the time until some of the switches started to wear out(they work, but release slow.).
http://www.usbgear.com/4port_sharing_hub/
thanks so it works just like a USB/card reader hub but instead works with 2 computers and just a single?
thanks for the reply
I later picked up 2 of these just before they stopped selling them(clearance).
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=1187801
Anyway, this is far off topic, but its all good