What you *could* do regardless of what FTP daemon you use, is write a little script that checks the existance and change date on the files (or directories), and if they are new - upload/mirror them to that other server. It shouldn't be too hard, and similar scripts should be possible to find to get ideas from or to use straight away. A quick Google turned up this page
, which also has a usable script. I don't really know what usability you had in mind so I can't say if it would work for you.