SP2 supposedly brings you Sharepoint web parts for navigating and displaying but i havent had a chance to find or use them yet.

I have seen a method of writing your own parm pages that show within Report Manager (from memory it was from the Hitchhikers guide to RS) but it was a little bit cludgy and very hard to maintain - i felt it was more to rpove a point that it could be done.

Personally, if doing it completely for intranet, i'd be looking at implementing the WS rather than URL calls, but this approach falls over really quickly if you need to do i) drill downs; or ii) have extranet access.

My 2c