I used to backup my computers on a cloud backup service. However, the concept never sat right with me. What if I have no wifi to recover the backup? What if the corporation hosting the online backup suddenly closes its doors? What if their servers are damaged? Where are the servers that have my data anyway? What if their encryption algorithm malfunctions when I need to recover?

So, I currently use a combination of Dropbox and local real-time backup. I know Dropbox is not that secure, but the convenience outweighs the lack of security for me. Also, I encrypt sensitive data before it's uploaded to the Dropbox servers. With Dropbox, all three of my computers have the same data in real-time. Thus, each of the three computers and Dropbox is a backup.

Further, I run a dedicated local backup that goes to an external hard drive by using the simple Yadis Backup program. It makes a real-time mirror backup with versioning. The whole system works so smoothly that I don't even notice it until I need a recovery.