The price of memory has been falling for decades. One terabyte USB drives now retail for less than $100. Backing up one's data has never been easier. But if your backup drive is in the same place as the primary data, is it really safe? A secondary backup to the cloud (ie. onto a server, far, far away) could be a failsafe solution. Carbonite offers unlimited, fully encrypted backup. The service streams your data up to servers, looking for any altered files. The only potential fly in the ointment is bandwidth -- if your broadband plan isn't generous enough, the initial backup of your files might max out your upload allowance and end up costing you extra. Ongoing backups wouldn't be as problematic, assuming you are not working with video or large image files. Backblaze also features unlimited backup, and promises to automatically find all of your personal files. There are many other services -- see the list here.