"Unique" download count?

I understand the difficulty in counting downloads (bots, uncompleted, etc), but is it possible to track "unique" downloads. By "unique" I mean that a download attempt by a given IP address would only be counted once. Of course, this could hide some attempts (folks behind a firewall or something) -- but I'd like to have this number.

I've checked through the docs and without trying out the software I'm not sure it's possible. I've also seen the other post here about visitors and downloads...but didn't think that fully answered this specific question.

Thanks