teleport is a simple prefpane utility to let you use one single mouse and keyboard to control several of your Macs. Simply reach the edge of your screen, and your mouse teleports to your other Mac! The pasteboard can even be synchronized between the computers.
It uses Bonjour to find available hosts. For controlling them, it catches the events of the master computer, sends me on the network using TCP, and uses some native CoreGraphics calls on the slave computer.