VNC is so Cool.
I am using this software at home to control my Fedora system and my Macintosh from my PC. I have dual monitors and I can control all three systems simultaneously from my PC. I even disconnected my Linux system from the two channel KVM I had.
I use the KVM now to hook up old computers I am donating to charity. Life is good. The software works pretty well with my small Ethernet network. I bet it would work even better with Gigabit Ethernet.
I set up less complicated single color background screens on the computers I am remoting, and response time for the mouse pointer is nearly instantaneous.