Stuff to Backup when you are reinstalling your Linux OS

> Home Folder
> Desktop
> Downloads
> Music
> Pictures
> Templates
> Ubuntu One ( This is already on Cloud but backing up can save bandwidth)
> Videos
> VirtualBox Vms

>> If you want to save old settings, bookmarks etc, you will also have to backup the hidden folders in the home folder. Typically each piece of software you install will make its own '.hidden' folder for your personalised settings & in some cases data as well

If you use Apache & MYSQL, You'll want to also backup the /var/www folder & any mysql databases