Synergy, an open source software application that allows you to control multiple PC’s through the TCP/IP LAN network.
You can control two systems over your network with just one set of K&M connected to one of the machines. I have a laptop and a desktop which are kept apart, this works great. I don’t have to reach out for the puny keyboard and track pad of the laptop every time I need to click on some thing. I can simply drag my mouse out of the boundary of the PC and voila! it starts moving around in the laptop’s screen.
This can be done with more than two systems as well. You can control more than two systems with synergy.
Here is a nice guide to get you started.
*Update 2/2018*
Synergy has since become a paid software. The alternative is to use Microsoft Garage project by Truong Do, known as Mouse without Borders. [ref. link]
Tags: Productivity Software Windows