I like Cyberduck (it is free) quite a bit, its a craftily-created FTP file transfer solution that in its latest incarnation adds Google Storage and Amazon S3 file versioning to its many talents, which now also includes the capacity to assign access permissions to different users (handy).
It features an easy to use interface with quickly accessible bookmarks. The outline view of the browser allows you to browse large folder structures efficiently. You can even quickly preview files with Quick Look. To edit files, a seamless integration with any external editor application makes it easy to change content quickly.
Both Amazon CloudFront and Cloud Files from Rackspace can be easily configured to distribute your content in the cloud. Many OS X core system technologies such as Spotlight, Bonjour and the Keychain are supported and 30 translations make you feel at home.
Using Cyberduck, one can limit access to files stored in Google Storage selectively to anyone who has an email address registered with Google. Access is granted only when logged in using a Google Account and authenticated against the ACL.
This solution is feature-packed and at its price (free) well worth adding to the virtual toolbox.
After all, it gives you a fabulous solution for cloud storage back-up, thanks to Google…