You'll find that a normal USB hub only has one upstream port. In other words, you won't be able to attach the cables.
There are abnormal USB hubs out there which allow you to switch from one computer to another. I have one. It's inside a Mitsubishi monitor.
There may be standalone hubs of this nature, but I've not been in the situation to need one, so I've not looked. You, on the other hand, have a use for such a thing. Good hunting.
[This message has been edited by denim (edited 12-01-2000).]