By Jenna Wortham May 7, 2009 11:30 am May 7, 2009 11:30 am Sure, the iPhone can double as a digital Sherpa to herd you around a new city, but what about when it comes to documenting your adventures? The current camera built into the device doesn’t make it an easy task — a 2-megapixel shooter combined no flash or zoom capabilities requires a steady hand, near-frozen subjects and an abundant light s