I've found that recently nothing has improved my productivity more than the free Synergy program (available at synergy2.sourceforge.net). With it you can connect several computers to one keyboard and mouse.
Unlike a KVM switch you simply pass your mouse into the screen of the computer to control, and you can even copy and paste between them. What's more the utility runs on all of Windows, Mac and Linux computers, so I now have five computer monitors surrounding my work area, each with a different operating system, and can now quickly test a piece of code I'm developing on a wide range of systems and different web browsers.
From the web site:
With synergy, all the computers on your desktop form a single virtual screen. You use the mouse and keyboard of only one of the computers while you use all of the monitors on all of the computers. You tell synergy how many screens you have and their positions relative to one another. Synergy then detects when the mouse moves off the edge of a screen and jumps it instantly to the neighboring screen. The keyboard works normally on each screen; input goes to whichever screen has the cursor.
You can arrange screens side-by-side, above and below one another, or any combination. You can even have a screen jump to the opposite edge of itself. Synergy also understands multiple screens attached to the same computer.
Running a game and don't want synergy to jump screens? No problem. Just toggle Scroll Lock. Synergy keeps the cursor on the same screen when Scroll Lock is on. (This can be configured to another hot key.)
Do you wish you could cut and paste between computers? Now you can! Just copy text, HTML, or an image as you normally would on one screen then switch to another screen and paste it. It's as if all your computers shared a single clipboard (and separate primary selection for you X11 users). It even converts newlines to each computer's native form so cut and paste between different operating systems works seamlessly. And it does it all in Unicode so any text can be copied.
Robin Nixon is a developer and technical writer and the author of Plug-In PHP: 100 Power Solutions (McGraw-Hill; 2010)
This story, "One Keyboard, One Mouse, Several PCs — Zero Hassle" was originally published by ITWorldCanada.com.