Utility of recursive queries?

Would recursive queries be the trick to doing things like unwinding a 
linked-list to either the head or tail, with:
create table list (    id int primary key,    parent int references list(id));
insert into list values (1, null);    -- head of chain in listinsert into list values (2, 1); -- 1st childinsert into
listvalues (3, 2); -- second child
 

Given a reference to id=3, would a recursive query be the trick to 
unrolling the list to discover id=1 as the head using a SQL one-liner? 
Is discovery possible in straight SQL w/o resorting to stored 
procedures (or modifying the table schema to directly point)? And, 
finally, would any potential recursive query implementation be 
noticably more efficient that a straightforward implementation in 
plpgsql, such as:

create or replace function find_head(int) returns int as 'DECLARE    cur_par INT;    prev_par INT;BEGIN    prev_par :=
$1;   cur_par := parent from list where id = $1;    WHILE cur_par is not null LOOP        prev_par := cur_par;
cur_par:= parent from list where id = prev_par;    END LOOP;    return prev_par;END;
 
' language 'plpgsql';


----
James Robinson
Socialserve.com