I choose to just double up on cloud services as a "backup"
EDITED to add link: https://tahoe-lafs.org/trac/tahoe-lafs
... That's about it.
I use gmail, but I don't trust it, and have been looking for an excuse to get away from it for a while.
I'm not very comfortable with other cloud services.
For me, it's a balancing act. I find it hard to manage backups. I don't want to run a RAID setup at home. I really like the convenience of Dropbox and S3.
I mean, yeah, obviously the primary concern would be "oh my god my house burnt down." But if you can minimize the repercussions by putting digital stuff which is important to you offsite, maybe that's something to be relieved about.
But yes, I mean it literally. Insurance may pay to replace your house. But a portfolio of a few years of work, the text of your half-finished novel, photographs of your children growing up, the final e-mails you exchanged with your uncle who died of cancer? No insurance money will ever replace those.
In the interest of full disclosure... I can barely muster trust enough for gmail. Actually, I don't trust gmail, which is why I don't use it for anything important or personal. I certainly would not put my child's photos onto a cloud service and expect them to be safe. And from what I understand, these people put, not only their data on iCloud, but their ACTUAL DEVICES are administrable from iCloud. That seems insane to me. It seems that this is the inevitable result of any such system.
I guess I am just a bit surprised at the surprise being expressed here. USB drives are not THAT horrible are they? They seem, to me, far more reliable backup methods.