getting the last N tuples of a query

Hi!

if a want the first 5,10,N tuples of a query (even without order)
i just have to do a:
select * from table limit 10;

but, What can i do to get the last 10 tuples ???
i try to do:
select * from table limit -10; :-D but that query return 0 tuples .

So, what is the right way to do that with no order????