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 list
insert into list values (2, 1); -- 1st child
insert into list values (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