formula to create list of unique items

Thanks for looking.

I have a column that looks something like (it is VERY long and has over 20 different names):
abe
abe
abe
abe
ben
ben
ben
cat
cat
john
john
john
john
tex
tex

I want to create another column (automatically) that lists each of of those once:
abe
ben
cat
john
tex

Any idea of how I can do this automatically?

Thanks.