I recently got stuck on an odd problem.
My friend hired a designer to work on a web site for his company. He asked my recommendation about a tool to allow web designer perform secure file transfers so that he can update web site. Since he's hosting on Windows 2003, my immediate recommendation was to enable webdav, which he did and the good old "Open as web folder" trick worked fine. Web desiner, however, wasn't so lucky. He worked on Vista, and they removed "Open as web folder" option from IE, also made it excruciatingly hard to use webdav in general. Another issue there was that the sire certificate expired, and all other 3rd party webdav solutions I tried didn't let me ignore that fact, so it rendered webdav to be not a good method in general for file transfer to give to outside contractors
I assume, noone would consider traditional FTP, since it's inherently unsecure, and requires 2 ports, which is a pin in the ass to begin with
I also evaluated SCP/SFTP, which are based on ssh. Those are good, but without chroot jail they give access to the whole file system. This was true for linux, but same appeared to be true for cygwin-based openssh installations.
Last thing I tried was FileZilla. Being pretty advanced FTP server, it apparently offers no SCP/SFTP server functionality. It allows FTP over SSH, but for that you need to buy certificate again. Or generate yours, but then you must compel your contractor to trust your root, not secure option again
I guess we're coming to a question - what tool do the people around use for their web hosting contractors (windows or linux) to allow controled, secure file transfer?