Código SQL:
Ver originalCREATE TABLE #temp
(
usuario VARCHAR(20),
fecha datetime
)
INSERT INTO #temp VALUES ('juan', '10/11/2011')
INSERT INTO #temp VALUES ('jose', '10/11/2011')
INSERT INTO #temp VALUES ('pedro', '10/11/2011')
INSERT INTO #temp VALUES ('luis', '10/12/2011')
INSERT INTO #temp VALUES ('jose', '10/12/2011')
INSERT INTO #temp VALUES ('juan', '10/12/2011')
INSERT INTO #temp VALUES ('antonio', '10/12/2011')
INSERT INTO #temp VALUES ('jose', '10/13/2011')
INSERT INTO #temp VALUES ('luis', '10/13/2011')
INSERT INTO #temp VALUES ('pedro', '10/13/2011')
SELECT * FROM #temp WHERE fecha = (SELECT MAX(fecha) FROM #temp)
Saludos!