From ArchWiki

The packages are all located in AUR. It is recommended that you use an AUR Helper to install them.

[edit] Packages

These are the packages that provide a way to mount FTP shares:

• curlftpfs [recommended]
• fuseftp
• lufs [outdated]

They are based on fuse.

[edit] Example using curlftpfs to mount a FTP folder

Install curlftpfs (it is in AUR) http://aur.archlinux.org/packages.php?ID=4498

If needed, make sure that fuse has been started.

#modprobe fuse

Create the mount point and then mount the FTP folder.

#mkdir /mnt/ftp
#curlftpfs ftp.yourserver.com /mnt/ftp/ -o user=username:password