At least one off site. I don't trust cloud computing[1], so I use sneaker power to get mine off site. So, what I do is keep a copy of my office filesystem at home, and a copy of my home file system at work. (This is probably only possible because of the sort of "environment" I have at work). I transfer the filesystems via a portable HD, which is another backup, actually. If I'm really keen to back something up from work when I'm at home (or the other way round), I use rsync over a ssh connection.
[1] For a while, I did use IBM's Tivoli backup, but that was at work, and done within the university.
Best wishes,
Bob