Inserting values into a SERIAL field

Hi all,

Is there any SQL statement to PostgreSQL that will allow me to insert rows
with a specified value for the SERIAL value. I know this is not what you
want to do normally, but I'm trying to provide a kind of general export and
import function to a generic database. Since there exists foreign key values
in instances of other tables that point into field values for a table that
has a SERIAL id, I'd like to somehow import all this data and continue using
the SERIAL functionality for the highest value of the id fields.

Ian