I've just discovered this excellent backup system:
-- free for basic use
-- lets you backup to a folder, another computer in your house, or a friend's computer (you cna be each other's off-site backup)
-- all backups are fully encrypted
-- does bitwise backup: only the parts of the file that have changed are added to the backup
Lots more at the link above, and there are reviews
here and
here.
[AVKDDEY]