This List feature was what convinced me it was worth upgrading to 2003
(haven't encountered the killer feature in 2007 yet).
The list should be structured like a flat database, with column labels in
the first row of the list (needn't be the first row of the sheet), no blank
rows or columns, and each row represents one record of the data. Select the
range (or a single cell within the range and let Excel expand the
selection), go to Date menu > List > Create List, or hit Ctrl + L.
Make sure your series formulas reference the data in the list by column. If
the list has its column headers in row 3 and data in rows 4 through 20, if
your formula includes all these rows of a column in the list, like
=SUM($G$4:$G$20), if the list is expanded or contracted, the formula will
automatically update so it still references the entire list.
- Jon