Don,
I wasn't sure if your question had to do with data handling on a CR web app, or just the viewer in general...
On the data, as a general answer, I believe that most (maybe all) of four methods that Craig described (ODBC, OLE-DB, ADO, or even Fox2x) could be accomplished.
With Fox2x, you'd need to have a different 'user folder' on the server, so that each user's report request would have server code copying fox2x data to the folder for that user.
I did that once in a Citrix environment - wasn't 'pretty' (we had \USER001 through \USER300), and if I had it to do over again I would have used ADO, but it did work.
If you were doing ADO, just have your queries on the server build an ADO recordset,and set the report's database object to that recordset.
If it's just the viewer, I only ever did what Craig suggested, downloaded the ActiveX viewer. If you search through the CR samples, I believe they have some samples of how to use it.
By the way, Craig's book would probably help you with many of these Fox-Crystal topics. I believe you'll find a reference to it on his site.
Kevin