Recently I came across a situation where we need to display a report with multiple SharePoint lists having one column “CategoryID” of type Number in common with minimum efforts or no code.
The environment expected for this solution was a Windows SharePoint Services 3.0; Which limits us from using Content Query Web part (which is MOSS only feature) with cross List Queries.
We came across a beautiful feature of Microsoft SharePoint Designer which facilitates to display data from multiple resources into a single Data View. http://office.microsoft.com/en-us/sharepointdesigner/HA100991441033.aspx
The sample explained here contains creating XML files for the Data Sources. Any Existing SharePoint Lists can be considered as a Data Sources.
Using this way we can easily create a dynamic view from multiple lists. Although the major disappointment here is : No Filter, No Sorting is supported. This will also not have Export to Excel feature as well
With Some play around using Microsoft SharePoint Designer on the Data View Web part we can achieve Grouping.