I've just added Netdrive 1 to my computer. It maps your FTP site to a Windows drive letter.
This means that you can open dual pane listers and have your FTP site listed as a drive in one and your local machine in the other, both with folder trees, something that DOpus can't do on its own.
It's freeware, by the way. Earlier attempts at doing this didn't run on Vista, apparently, this does.