Generating Dropdown Lists
 

I have a worksheet with multiple columns of data. I want to create a filter
that is based on values for each column that the user selects. Each column
has data that is repeated within the column (i.e. "Mike" may appear a dozen
times in one of the columns). I would like to create a dropdown list for
each column that only has one entry for each value in the column (i.e. "Mike"
would only appear once in the dropdown list). The number of rows is not
fixed.

Right now I expect that I'm going to have to generate an intermediate
worksheet that filters out the repeated values of each column. How would I
go about this? Or, is there an easier way?

Any help would be greatly appreciated.
Mike