smittal - are we talking about different workbooks here? Or is everything in the same workbook, on different tabs. If everything is in one workbook, then this question is similar to http://chandoo.org/forums/topic/creating-a-priority-table-from-multiple-tables
At that post, I suggested that we have a summary table that a macro clears any time the Summary tab is activated, and then the macro copies the info from the other tabs into the blank Summary table. Good thing about this is that you can then point a pivot at that summary table, and do business intelligence stuff on the amalgamated results.
If the files are in different workbooks, then you could use SQL to amalgamate the data to a pivot table. THere's an example of this at http://blog.contextures.com/archives/2010/08/30/macro-creates-excel-pivot-table-from-multiple-files/ that could likely be easily amended to suit your needs.