To create data bars in Excel, select your cells and then choose data bars from Conditional Formatting.
Excel Conditional Formatting already lets you format cells based on the value of those cells or the value of the formulas in those cells (see our conditional formatting tutorial for more details). Now ...
When you've got a chart-heavy Excel spreadsheet, you can display one chart and let the viewer switch to see the others from a drop-down. The Pointy Haired Dilbert blog runs down the details of this ...