I recently created some Powershell scripts to perform basic FTP commands.  A description and link to each script is included below. 

Disclaimer: These scripts are intended for learning / demonstration purposes only and I provide no guarantee of their performance.  If you plan to use any part of this code in a production environment, I recommended testing it in a development environment first.

Ftp-AddItem.ps1: The Ftp-AddItem cmdlet adds new item to FTP site.

Ftp-DeleteItem.ps1: The Ftp-DeleteItem cmdlet deletes item from FTP site.

Ftp-DirectoryItemCount.ps1: The Ftp-DirectoryItemCount cmdlet returns a count of all items on FTP site as an integer.

Ftp-DirectoryItemSize.ps1: The Ftp-DirectoryItemSize cmdlet returns total size (in KB) of items on FTP site as an integer.

Ftp-GetItem.ps1: The Ftp-GetItem cmdlet gets item from FTP site.

Ftp-ItemsToProcess.ps1: The Ftp-ItemsToProcess cmdlet returns list of files on FTP site as an array.

Ftp-RenameItem.ps1:  The Ftp-RenameItem cmdlet renames an item on the FTP site.