Review my startup: Conflict-free, multi-master file replication
cabalamat: I would also suggest that when you have the boxes installed at a customer's site, it may be an opportunity to sell more stuff to them, by adding functionality to the boxes. For example, a customer might want VPN and if they are happy with the Synctus boxes, might want it to go through them. Or perhaps a corporate wiki, replicated through all sites in the organisation. Or accessing some or all the shared files by ftp or http. Or a revision control system -- you getb the idea.