Excel's AutoFilter feature makes filtering out subsets of your data as easy as selecting an option from a drop-down list. In fact, that's literally what happens. When you convert a range to a list, Excel automatically turns on AutoFilter, which is why you see drop-down arrows in the cells containing the list's column labels. (You can toggle AutoFilter off and on by choosing Data, Filter, AutoFilter.) Clicking on one of these arrows displays a list of all the unique entries in the column. Figure 13.8 shows the drop-down list for the Account Name field in an accounts-receivable database.