I often use both my laptop and my desktop at the same time. This means I have two mice and two keyboards on my desk.

I recently discovered the free and open-source application Synergy. This program lets me use the same mouse and keyboard for the multiple computers by just moving my mouse from one screen to the other.

It is really easy to set up. You download Synergy for you operating system (Windows,Linux or MacOS) and install it on all the devices you want to use it on. Then you startup the server on the computer with the keyboard and mouse attached and the client on the other computer(s).

Disclaimer: Although this post sounds like one big advertisement, it is not. I just like the program and did not receive money for this post.

[Via Synergy]