I recently heard about a really cool open source software program on Leo Laporte's radio show "The Tech Guy". It's called Synergy. The software allows you to share the keyboard and mouse of one computer with other computers, and it does this all through software, no hardware needed. The typical way of doing this in the past was by installing a hardware KVM switch that you physically hooked your keyboard and mouse up to (and video, if you want), and then had to either physically press a button on the switch, or press a hot-key on the keyboard to have your keyboard and mouse switch to the other computer.