Craig, a regular reader here, asked a cool question. He has a list of numbers where one column is a cumulative total, similar to this
The last column is an accumulation of the second column. The problem is when the data is filtered. The cumulative column still shows the same accumulation, not just the accumulation of visible cells. The SUBTOTAL worksheet function works with visible cells, so that seems like a nice solution to this problem.
Now when the data is filtered, the cumulative column is updated to reflect the proper amounts.