Let's not leave out Windows 2003 R2. With the new DFS (Distributed File System) you can simplify file sharing acrous your entire domain (multi sites). DFS allows you to create a single namespace for file shares that are located on different servers, redirecting remote users as required to the correct physical locations. Among other niceties, DFS is site aware: Based on the IP address of the user accessing a DFS share, DFS will ensure that they're using the closest possible DFS server. Abstraction in DFS is important for a variety of reasons, but the most obvious is that administrators can move shared folders to different locations, even on different servers, without disrupting or even informing users of the change. FRS has been succeeded by a new DFS 2 technology called DFS Replication. DFS Replication uses a multimaster replication model that allows DFS-based data to be replicated more efficiently over the network than was possible with FRS. A good part of this efficiency is due to a new technology called Remote Differential Compression (RDC) that replicates only those parts of a file that have changed, dramatically lowering network bandwidth. If you change the title in a PowerPoint presentation, only that title change will be replicated across DFS, not the entire file. This is far more efficient and, ultimately, less expensive.