I like Blogger's new export feature (you can also do imports), which allows you to create a backup of your blog via an .xml file you save to your local machine. A good first step, now I am waiting for the next step of allowing one to backup (or sync) directly to an online storage site. Maybe Google Drive.
I manually backed mine up a threw a copy on SkyDrive. I am not taking up very much of my 25GB at this point.