Just when you thought Numark couldn't invent any more DJ controllers, it's done it again. This time it's MusikMesse at Frankfurt, with the little guy you see above -- the Mixtrack Edge. It's described as "ultra portable" and when you see how big it is -- roughly the size of an iPad -- we're inclined to agree with that. In fact, when you see the device cooped up in its protective case with the lid down, you'd be forgiven for thinking that's exactly what it was (a
