Compare values from the most recent row to the one just before it

Hi all,

A table has a timestamp t, and some numeric column, n

I need sql statement that would compare n from the row where t is max [max(t)] to:
 the value of n in the row where t is right before max(t)
-- OR --
 the value of n in the row where t is the second before max(t)

To clarify:
t                                           n
2013-01-28 19.00.00           23
2013-01-28 19.00.01           88
2013-01-28 19.00.02           2
2013-01-28 19.00.03           3


I need sql statement that would compare 3 to:
 2
-- OR --
 88

Any help is appreciated