I've recently implemented phase 1 of a double-tap zoom hack for the Diablo GTK webkit, so I spent some time staring at how the iPhone OS webkit implements zoom. It's simple. They just do an animated 2D transform while another thread is rerendering the page. They time the animation such that the final pixel copy happens soon after the animation finishes. If you have such a device, you'll notice that your screen is frozen to UI while this is happening. After the zoom is complete, you have to reregister your onFingerDown event. Nothing will happen until you do. A simple parlor trick, nothing more. Nokia could do this, but instead they decided to show you the continuous output of your appSSS. Plural. So, now all you eye candy weenies know.