Duplicity + S3: Easy, cheap, encrypted, automated full-disk backups
I use Arq[1] on my macs and it does the same thing but handles all the "complicated" bits that I'd rather be programmatically dealt with.  I have 6 macs, about 2TB of backups in Glacier and a ~20GB "system image" backup in hot-storage on S3.[1] http://www.haystacksoftware.com/arq/