For each key, find row with highest value of other field

I have some data of the form:

Key | Date       | Value
A   | 2008-05-01 | foo    *
A   | 2008-04-01 | bar
A   | 2008-03-01 | foo    *
B   | 2008-03-04 | baz
B   | 2008-02-04 | bar
C   | 2008-06-03 | foo    *
C   | 2008-04-04 | baz
C   | 2008-03-04 | bar

Is there any way to select only the rows marked with a (*) out of these 
without doing a join?  I.e. I wish to find the row with the highest 
Date for each Key and use the Value from that.

Regards,

-- Raju
-- 
Raj Mathur                raju@kandalaya.org      http://kandalaya.org/      GPG: 78D4 FC67 367F 40E2 0DD5  0FEF C968
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