Are you work at the office that daily activities always using Office software? Office application that known this day are Microsoft Office and OpenOffice. Microsoft Office is the commercial one, that user must have a license, OpenOffice is a free one and available to OS base on Windows of Unix.
Now OpenOffice release portable version that practice and flexible. OpenOffice portable can be store on portable media or removable media so we can bring wherever we go. All office application like word processor, presentation are in your arm. You can run your OpenOffice on every PC as long as you can connect your removable media to the PC. In other word, you don't have to make any installation. This software is very suitable to the traveler but doesn't want to bring PC or laptop.