Crackup is a pretty simple, pretty secure remote backup solution for folks who want to keep their data securely backed up but aren't particularly concerned about bandwidth usage.
Crackup is ideal for backing up lots of small files, but somewhat less ideal for backing up large files, since any change to a file means the entire file must be transferred. If you need something bandwidth-efficient, try Duplicity. Crackup is a quick and simple (but secure and reliable) hack that gets the job done, but not much more. My main reason for writing it was that I needed something similar to Duplicity that would work well on both Windows and Unix systems. Crackup runs well on Windows under Cygwin.
Backups are compressed and encrypted via GPG and can be transferred to the remote location over a variety of protocols, including FTP, FTPS, and SFTP.
I just put the finishing touches on the first usable version of the backup client a few minutes ago and it seems to work well. There's no restore client yet, but it'll be easy to whip up as soon as I get around to it (which will hopefully be before I need to use it).
Update: crackup-restore is now complete and is available in the SVN repository along with the rest of Crackup. Enjoy!