The new visualization feature of Excel 2007 provides users several methods of graphically representing numerical data, making it easier for them to understand relationships and trends. User can add data bars to the columns of data, allowing them to visually observe how large amounts are relative to each other without actually having to look at all the cell values. User can even configure it so that each level of the pivot table has its own set of data bars, showing just the relationship to other entities at the same level.
User can also add color scale visualization to the Data column.  This allows them to quickly determine which data pieces have the high/low value, simply by looking at the colors of different cells. Icon set is another way for the user to visually represent the data in a column, making it very easily for the user to relationship between cell data.