Trigger function to audit any kind of table

Hello,

I would like to know if it is possible to create a trigger function which
does something like

CREATE OR REPLACE FUNCTION table_audit() RETURNS TRIGGER AS $table_audit$
BEGIN
INSERT INTO audit SELECT TG_OP, current_timestampmp, current_user, OLD,
NEW;
RETURN NEW;
END $table_audit$ LANGUAGE plpgsql;

Can I create a table with those two RECORD pseudo-types or something
compatible?

I'm using pgsql 8.1

Thanks.