Retrieve primary key after inserting

Hello all,

Is there a special mechanism to retrieve the primary key from a record that I
just inserted?

For example, I have a table with the PK of SERIAL type. So when inserting I
let the psql to choose the primary key. But how can I get the primary key
that was set for the record? BEcause i have a relation based on that primary
key... !!! (I think it is a classic problem...)

Does psql have some special feature to help me overcome this problem ?

Tx
dovle