I'm using my NAS4Free Embedded box as a backup server for my home lan. As NAS4Free doesn't have a rsnapshot plugin, I decided to install rsnapshot myself (embedded version)
You may find my my howto useful if your want to roll you own rsnapshot setup.
http://blog.koospol.nl/rsnapshot-on-nas4free-en.html
Enjoy your backup
Ceaus