The listing, Sakar 4 Port USB A/B Switch Hub has ended.
http://www.juggle.com/sakar-72260-4-port-usb-hub
Please read the link for a technical description. This is only the unit, no cables included. You can power it with a 5v adapter if you choose to.
You can even use it on one computer and use it to shut off unused devices without plugging them in and unplugging them all the time, prolonging the life of your device! Great for turning off your webcam, turning off the printer connection, and turning off external drives. Of course, when you use it between two computers, that's when it's good. With one push of the button, you can divert the usb device's signal from one machine to another - making it easy to share a single external drive, share documents, music, pictures and video via a thumbdrive - even share a webcam!
Good luck to the winner!