Augmented reality applications to this point could be best categorized as tantalizing to the mind, but otherwise pointless. Thankfully, it seems as if that's no longer the case. AcrossAir, a nascent app builder for the iPhone, has conjured up a slickly executed digital guidance application that augments video with real-time distance and directions to the nearest subway station. With the iPhone 3GS pimping an improved camera, inbuilt compass and GPS, we had a hunch that it wouldn't be long before someone slammed them all together and gave commuters and tourists alike a reason to smile. Presently only c
