Apple have dropped the FTP Server support in Mac OX Lion.However the FTP Server can be activated via the command line.
You can still enable it with the command line. To start it type the Terminal command:
sudo -s launchctl load -w /System/Library/LaunchDaemons/ftp.plist
To stop it:
sudo -s launchctl unload -w /System/Library/LaunchDaemons/ftp.plist