Directory Opus has a built-in FTP client that lets you access remote FTP servers as if they were local folders. You can copy, rename and delete files, create folders, and even view pictures as if they were files stored on your hard drive instead of on a remote FTP site.
There are a number of ways to connect to an FTP site in Opus:
Your FTP Address Book entries can also be displayed in the folder tree and the Jump List.
More:
FTP Address Book
Adding a new Site
FTP Connect
Site Properties
FTP Log
FTP Paths