Assuming that your data are in A1:A100 you could use following conditional
formatting formula for A1 (Menu Format|Conditional Formatting):

=COUNTIF($A$1:$A$100,A1)1

apply the desired format for this condition, push 'OK' and copy the format
down to A100 (easiest way is to use the format painter).

JM



wrote in message
...
If I have the following:


Column A

Mike Soren
Jim McGree
Paul Jackson
James Banton
Mike Soren


How can I have a formula that notices I just entered in "Mike Soren" a
second time in column A?
and maybe it will change the color of the text? or sound a warning
beep?