[djo]

What exactly do you have in mind? I don't think you want to give players ftp access to your game directory, or they could retrieve/upload anyone's turns, or the fatherland file. If you have them upload do a different directory, you have as much file management (approximately) as a PbEM game. How do you imagine this working?

That being said, Macs do have file sharing and ftp daemons. File sharing can be enabled from the Sharing panel of System Preferences. I think for OS X client edition, you need to enable ftp from the command line. OS X server has a GUI for it. Also, you might want to use sftp instead of ftp in any case (ftp tunneled over ssh).