Duplicati is a free backup client that securely stores encrypted, incremental, compressed backups on cloud storage services and remote file servers. It works with Amazon S3, Windows Live SkyDrive, Google Drive (Google Docs), Rackspace Cloud Files or WebDAV, SSH, FTP (and many more).
Duplicati is unique in that it will encrypt your data prior to uploading to the cloud. Keeping your data safe from prying eyes.