Dropbox

Dropbox is a free file synchronization service available for Windows, Mac and Linux.
Imagine you create a folder on your personal computer and all files that you place in that folder are available on all your computers where you install Dropbox. In short: you don't need to move your files from home to job place back and forth with a USB stick anymore. Just store all your needed files on this Dropbox folder and you get them anywhere in the world where you have a computer. It is also useful for sharing files with your friends because the user can create subfolders with share rights for specific friends. The files can be accessed from the Dropbox webpage too with a computer, tablet or a mobile phone.
Using the referral link bellow to register will give you an extra 500 Mb for free. You can also invite your friends to join and both of you will get additional 500 Mb.
Install Dropbox for free here.