"at" at end of sentence

[Laurence Horn]

>This final "at" was perfectly ordinary in Detroit during my childhood. I
>can hardly believe that our cousins across the river in Windsor ON were
>completely uncontaminated. It is my impression that the final "at" adds
>useful redundancy in some cases. If I'm not paying attention, "Where IS
>it?" sounds about like "What IS it?" etc., but "Where's it AT?" is clear
>enough. "Where is it?" however has been OK everywhere I've been (I think);
>is anybody suggesting that in some region the "at" is nearly obligatory?
>
>-- Doug Wilson

Another possible kind of non-redundancy:  As someone suggested
earlier in the thread, there's often a restriction (in some dialects)
of "where's it at?" to metaphorical uses; this indeed became a catch
phrase on this use for a while in the late 60's.  There's a line from
Dylan's Blood on the Tracks cut "Idiot Wind" (1975) which has always
struck me as playing on this, evoking the distinction between the
"sweet lady"'s dialect in which this catch phrase is used with its
customary metaphorical value and the singer's dialect in which it can
have an ordinary ("redundant") literal locative meaning, which
results in an interesting antecedent for "it" in the context (at
least on my interpretation):

Even you, yesterday
you had to ask me where it was at
  I couldn't believe after all these years
You didn't know me better than that,
                      sweet lady

larry