Synergy allows you to use several computers and displays with one keyboard and mouse. I've used it to combine our two single-head computers and a laptop into a system with three displays. Of course I had to arrange all the displays next to each other.
When I'm logged in on all the computers I want to combine, I run a script called start-synergy on the system whose keyboard and mouse I want to use. It automatically starts synergy software on all the machines and connects them over encrypted network connections.
start-synergy uses another script called remote-synergyc, which does the actual work of contacting all the other computers and sets them up as slaves. It uses ssh to establish the connection and to start synergyc. Further, it can use the output of who to find out the user's X server in the case there are several users logged in.
http://www.iki.fi/Tuukka.Hastrup/software/synergy
© 2003 Tuukka Hastrup (Tuukka.Hastrup@iki.fi)