From David Kocher, author of Cyberduck:
I am pleased to announce the release of Cyberduck 3 for the Mac. This is an important milestone for Cyberduck, most notably introducing native support for uploading files to two major content distribution services in the cloud. Both Amazon CloudFront (in conjunction with Amazon S3) and Cloud Files from Rackspace can be easily configured from within Cyberduck. Additionally to these major new features, we continue to further improve the integration with OS X (see below) and enhance WebDAV interoperability.
That’s right! Now you can access your Cloud Files data (even your CDN-enabled data!) directly through Cyberduck.Here’s a screenshot demonstrating how easy it is to share your Cloud Files content via CDN.

Cyberduck 3.1 is available for download here.