http://www.haystacksoftware.com/arq/index.php
It can act as a frontend to Amazon Glacier, just punch in your Amazon API keys. Considering ingress into the Amazon world is free and it's a penny per GB per month to store, I've basically paid $1/month to keep 100GB of personal data safely backed up at Amazon.
I'll need to pay more than that to get my data back out, because Amazon charges retrieval fees to get things out of Glacier, but if my on-location backups should fail to rescue me, then this has my back.