Aside from my belt-and-braces approach of Raid-5 storage, and regular backups to a separate drive, I wanted to make sure my numerous websites and blogs were also backed up off-site.
For WordPress blogs I have installed the following Plugin:
WordPress Backup to Dropbox
It’s been running a month or so now and appears to work well. I have it backing up regularly and will purchase more Dropbox storage if required in the future. You may even be able to do this with Google Drive in the future if you can get more free space there.
There are some premium features which may save you some space and money in the long run: Zipping up backups before uploading in particular.