Hi. I have several offices in China and 2 in the US. I would like to provide access to select folders to each one. I want them to upload several large files per day to each. How can I accomplish this in the most efficient, and soct effective way.

You could do this with a Equallogic or Compellent array for your back end stroage at each site. With Equallogic you could have a third that just handles replication (DR Site Recovery) for all the volumes, if something were to happend to the site locations.

Then use Microsoft DFS(r) to span data to all the locations. Allowing the file tree to stay sync'd. Each site should have a Active Directory server allowing you to sync permissions with folders across your domain.

You can also do it with linux and NIS/Samba and few other tools if linux is your enviroment.