How do we combine and return results from multiple queries in a loop?

Hi there,
We'd like to use a plpgsql function to use results from query A to execute
several queries B, C, etc., and return the results of all B, C, etc queries
as one result set. Would placing 'RETURN QUERY' inside a loop automatically
concatenate all 'return query' results in the function's return? If not, how
would we go about getting this result?

Here's an example. The function finds all zip_code records with the given
code, and then searches all locations for a state of that original zip_code.
(I know the current query could be done via a join, but my ACTUAL query
would require this functionality.)

begin;
create OR REPLACE function t() returns setof locations as
$$
declare z zip_codes%rowtype;
begin
for z in select * from zip_codes where code like '%32301%'
LOOP
return query select * from locations where locations.state like
z.state; #query B
# All I want to do is return the results from all of the above
queries as one
# result set.
END LOOP;
return;
end
$$
language 'plpgsql';
commit;

Any idea how I do that?