!! Introduction
If you have a media PC hooked to a TV and another PC right by the couch or wherever you are sitting, Synergy can be a cool solution as it will allow you to control the media PC with the mouse and keyboard of your laptop simply by moving your mouse outside of your screen on the laptop.
Since Synergy is not secure, you need to use SSH and make sure synergy opens its more on 127.0.0.1 and not on your regular network interfaces. On windows your typical firewall will warn you if you forget to do that.

!! Ingredients

You need synergy on each PC.
You need ssh/openSSH on each PC.
On Windows, it's best to just get SSH from Cygnus.

!! Recipe

Configure Synergy server on laptop (the controlling machine where you use the keyboard and mouse is called the server).