Here’s how you can start the FTP server in Mac OS X Lion:
1. Open a terminal window.
2. Type in the following command:
sudo -s launchctl load -w /System/Library/LaunchDaemons/ftp.plist
3. To turn it off, type in the following command:
sudo -s launchctl unload -w /System/Library/LaunchDaemons/ftp.plist