A simple search for "voting ip" or a more sophisticated Super Search would have turned up a very recent thread on this exact subject.

The main problem I see with allowing "poll" votes by login is that it makes it easier for the average monk to vote twice: once logged in and then once not logged in for their IP address.

But since we have our first real complaint (at least I think the previous cases were "predictions of complaints"), perhaps it will soon be time (after "apply/undo patches" gets crossed off the to-do list) to switch to the method you suggest. (:

        - tye (but my friends call me "Tye")