|Tigerdirect has a device from some company that you buy just for that. It allows many users to access a single workstation. I forget the name of the thing but there are a few models. Some offer usb and sound but the basic one has kvm.|
Other than that, you'd need some sort of thin client to be used.
They do make KVM's too that may be useful but they are normally many computers to a single display not the other way around.
Why did it take me over a year to phone in a problem to ATT?