Dropbox is a great service for online file backup. It integrates well with your desktop. All you have to do is drag and drop your files into a folder and automatically it will sync and store your files online. This is a great way to keep your files accessible from anywhere and you can even use your browser to upload files. Other great features are collaborating on a file between several users and syncing a file on multiple computers. Dropbox gives you 2 GB of space for free and you can upgrade if you need additional space. Dropbox works on Linux, Windows, Mac OS X and iPhone. Visit the dropbox site to learn more.