PivotPoint Web Part is a web part for Microsoft SharePoint® that allows you to perform Cross Tabulation on your lists in a similar way to Microsoft Excel's Pivot Table feature.
A CrossTab takes a list of flat data and then summarises the data over multiple axis - giving you new insights into your data.
For example it could take a list of Sales and present two different tables - one showing Sales growth over time for each product and another showing sales by region for each product :-