Augmented Reality wasn't supposed to come to the iPhone until its launch of OS 3.1, but in a surprise move, Yelp sped things up and introduced it in an Easter Egg within its own iPhone app. To unlock the feature, users must launch the Yelp app in an iPhone 3GS and give the phone a few good shakes. Once activated, users can point their iPhone cameras to any street and Monocle will overlay information for nearby restaurants