Synergy is a cross-platform tool which lets you easily share your mouse and keyboard between multiple platforms. If you use more than one computer at the same time, then Synergy will improve your productivity by allowing you to use just one mouse and one keyboard to control all your computers.

Synergy is available on Linux, Windows and Mac. To install it on Ubuntu, download the .deb file to your home folder (here), then run the following command in a Terminal: 

sudo dpkg -i FILENAME.deb

NOTE: You must replace FILENAME with the name of the file you've just downloaded.