How do i return a dataset from a stored procedure

I can't figure out how to return a group of rows from a function
written in plpgsql (or plsql for that matter). The only way i have
seen it done is with a setof table return value in sql. But since the
query was a single select anyway i don't see the point of this. Is
there a way of creating a temporary table in a procedure and using it
as the output?

thanks