Sometime ago I wrote a FTP proxy to RackSpace Cloud Files which expose Rackspace Cloud Files as a FTP server acting as a proxy.
Thanks to the OpenSource community a user on github took it and add support OpenStack and all the latest features available in Cloud Files.
It is now pretty robust and works pretty well via nautilus even with the pseudo hierarchical folder feature. The fun part here is that it allow you to effectively have a Cloud Drive where you can easily store your files/backup from your Linux desktop via nautilus built-in ftp support.
I have made a video that show how it works :