Deploying and Configuring Internet Information Services (IIS) 6.0 with Remotely Stored Content on UNC Servers and NAS Devices

There is a great whitepaper available that explains the "ins and outs" of using file servers/UNC paths for hosting content.  The document's original link had been missing from the MS web site for quite a while and I has happy to discover that apparently it's been reposted as part of the IIS 7 documentation.

You can now find this informaiton here:
http://technet.microsoft.com/en-us/library/dd296641.aspx