1. Install curlftpfs

   suda apt-get install curlftpfs

   2. Install rsync

      sudo apt-get install rsync

   3. Create mountpoint

      mkdir /path/to/mount

   4. Mount remote directory

      curlftpfs ftp.example.com /path/to/mount

   5. Create local directory

      mkdir /local/path

   6. Rsync mounted directory to local directory

      rsync -r -t -v --progress --bwlimit=500 /path/to/mount/ /local/path/

[http://www.wikihow.com/Mirror-an-FTP-Directory-With-Rsync-and-Curlftpfs]

[only for ubuntu gutsy feisty (>7.x)]