DFS is a very interesting Microsoft Server feature that give you the ability to replicate and aggregate shared folders (integrated in Windows domain too) on different sites and with differential approach about bandwidth saving feature.
In case we would like to replicate same data on different location and we would be sure that only a person can modify single file we should, in this case, advice all the other users that would like to modify that file that (on different geographical server with same replica data) it can be opened only in read only mode.
I got notify that this software can do that job, here is relative link (it is not for free)
http://www.peersoftware.com/products/sync-backup/peersync-for-servers.html
