Synergy+ shares one mouse and keyboard between multiple computers
Synergy is a cross-platform, open source application that allows you to navigate between multiple computer systems using a single mouse. Each system has its own screen, and once Synergy is installed and configured correctly, you can simply move your mouse to the edge of one screen and watch it seamlessly jump to another screen, which is a completely different computer.
We've talked about Synergy before, but unfortunately, development on it stagnated in 2006. Thankfully, there is a project on Google Code called Synergy+ which has taken the source code of the original Synergy, written by Chris Schoeneman, and updated it with numerous bug fixes. The team behind Synergy+ seems to want to continue improving the product, and they would welcome Schoeneman back, even to the extent of hoping that he would merge the two projects if he ever returned to active development on Synergy.