SQL: selecting the first login of a user

A friend of mine asked how he could select the first appearance of a user in a table having the timestamp when the row was inserted.

A data sample follows:

date, user

2010/12/10 11:32, john

2010/12/10 12:32, john

2010/12/11 12:20, mary

2010/12/12 12:20, mary

2010/11/11 10:20, peter

And the he wanted to get:

2010/12/10 11:32, john

2010/12/11 12:20, mary

2010/11/11 10:20, peter

So a came up with the following query:

SELECT t.user , t.date FROM test AS t WHERE t.date IN 
(SELECT MIN(DATE) FROM test WHERE USER = t.user )

I am not an SQL expert so I bet that someone can write a more optimized query so if you are the on, please send it over 🙂

EDITED: A better approach by @jbarrio

SELECT t.user , MIN(t.date) FROM test AS t GROUP BY t.user