getting back autonumber just inserted

hello

i ame a newbie to PostGreSQL, I ame using PostGreSQL 8.0 
(windowsinstaller) on a xp prof platform

i would like to get back the autonumber from the last record inserted, 
for other SQL db (m$ sql db ...) i could use:
SELECT @@ IDENTITY

can someone help me by informing me what the SQL syntax is to be used 
with PostGreSQL db and get the same result, the last autonumber inserted?

greeTz

wes