On Thu, 24 Jul 2008 00:22:01 -0700, why-J
wrote:

I have a very simple two column list. Col-A is "Products" col-B is "Date
Purchase". Col-A is un-sorted and various products are repeated several
times. I want a lookup formula that would tell me the most recent date when a
particular product was purchased.

If col-A was sorted ascending, I could use
=LOOKUP(1E+100,INDEX(A2:B8,MATCH(A12,A2:A8,1),0)) . Can someone please help.

Try this formula:
(Note: This is an array formula that has to be confirmed with
CTRL+SHIFT+ENTER rather than just ENTER)

=MAX((A2:A8=A12)*(B2:B8))

Hope this helps / Lars-Åke