How can I operate 2 XServes and 2 iMacs from 1 keyboard and 1 mouse (both bluetooth)? I have 2 Xserves and 2 iMacs.  I would like to control them with 1 Apple wireless keyboard and one Apple Magic Mouse.

I have seen a device from IOGear a Bluetooth 2.1 USB Micro Adapter,  which made me wonder if something like the following could work:



To do this I would need two 1 x 4 passive usb hubs with some kind of electronic or mechanical switch.  Then, plugging the bluetooth to usb adapters into each such device I could pair the keyboard or mouse with the respective bluetooth to usb adapter.

Do any such switchable usb hubs exist?  Could I use anything else?  Since I can readily share the displays of my iMacs via a mini dvi connection to the XServes I don't really need a full blown KVM device.

I saw a post on this site that recommended Synergy to do something like this, but as I don't have dedicated monitors for the servers, it does not look like a good solution for me.

Any other solutions welcome.

Thanks in advance.
I use a combination of synergy for my laptop (macbook pro), and workstation (ubuntu linux). To get to my servers (some freebsd, some linux) I use just SSH, but if I need an X session I can export it over ssh. As Lyken mentions, ARD is the way to go. VNC is more crossplatform, but since you're running all Macs, its a piece of piss to get working. 

Synergy would be worth a go with your two iMacs. 

With that setup, you won't need any extra hardware, just a working network.