The next major release of Cyberduck will support WebDAV. WebDAV, an acronym for Web-based Distributed Authoring and Versioning, is described as “…a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers”.
Although, the Finder.app does support WebDAV, first comparative tests show performance is much better in Cyberduck and browsing feels snappier. Because .mac is based on WebDAV, it will also be possible to access your iDisk using Cyberduck by mounting the URL http://idisk.mac.com/membername
as described in this support document.
Cyberduck 3.0 is expected to be released later this next month. The current nightly build (use with caution) is available for testing.