Strongspace Rsync Backup plugin
This is a plugin for the Strongspace gem to automatically backup any local folder to Strongspace. Currently it only works on Mac but will support windows soon enough.
It is a trivial edit from iTunes Plugin
Upgrade/Install the Strongspace gem to v0.0.9 or newer:
sudo gem install strongspace
Install the Strongspace Rsync plugin
strongspace plugins:install git://github.com/expandrive/strongspace-rsync.git
See the iTunes Plugin for usage info, and anywhere you see 'itunes:' replace with 'rsync:'.