Having decided to use Windows SharePoint Services (WSS) as a company-wide document repository I'm thinking I'm probably going to need to report on the documents and list content (in combination with data from other enterprise systems) and not just rely on SharePoint Search, so Reporting Services seems like a sensible option. Clearly though RPTSVCS can't do this out-of-the-box so I'll need to write a data processing extension. So I thought I'd see if anyone else had tried so far...

Other than what I read in this thread, and this one so far no-one has written an extension for accessing a web service (or at least, if Bryan Keller hasnt found it the I doubt it's out there yet). So I doubt theres one floating out there for accessing info in WSS and I'll need to roll my own. I found these links which I think will prove useful, any other pointers would be welcome:

File Share Extension
XML Data Extension
Clarification on the Placement of CodeGroup Elements for Extensions
How hard is it to write Reporting Services extensions?

If I manage it I'll post and article here!

UPDATE: Ohad has listed some other useful links including two for extensions for custom ADO.Net DataSets by Gavin Joyce and by a GotDotNet community

UPDATE 2: I have converted the original GotDotNet sample to VB.Net and it works! Now to write one to work with web services and ultimately with WSS lists so I can report on WSS lists to my heart's content...