Finding duplicates in Excel.

I've been asked how to do this several times now, so it seems like it isn't obvious to all, but is easy.

Step 1, sort the data on the column you want to find the duplicates in.
Step 2, create a new column. In the first cell of the new column (assuming row 2, column B is the first cell of the column containing the possible duplicates), enter =B2=B3
Step 3, copy the new cell down into the other rows. The cell will evaluate to TRUE if a cell is the same as the next cell down.
Step 4, put an auto filter on the data and set it to just display TRUE entries for the new column
Step 5, you are now looking at just the duplicate data.