http://h34nug3iwqjf2376fmmzdhgqivckzemcujmarlptfqeqtq7vya47yyad.onion/2008/01/16/synergy-sharing-the-keyboard-and-mouse/index.html
One of the first solutions that firstly came to mind was to use only one set of keyboard and mouse to access the other computer through some kind of terminal software such as VNC, ssh, FreeNX,… but, sometimes we would prefer to really use the other computer, providing us with access to two real screens (very comfortable), for graphical design tasks, games, closer feeling to the user interface, etc.