I just installed Redhat 8 on a new box, with its own monitor. I then installed x2x on my primary (Redhat 7.2 w/ lots of mods, like a Gnome 2.1 install thanks to Ximian and other random crap) box. And I already had x2vnc running to my laptop, on my right.
So now I have my three monitors like this:
[ redhat 8 ] [ redhat 7.2 ] [ win2k ] [keyboard] [mouse]
and I can control them all from that one kb mouse, just by dragging the mouse from monitor to monitor like a virtual display. Hell, it IS a virtual display, it's just a virtual display across multiple OS's.
Heh, I'm such a dork. I love this stuff. :)