Popular Yelp has updated it’s iPhone app to include a pretty cool easter egg. Shake your iPhone (3GS only) three times and, viola!, a hidden monocle feature appears. Click the top left tab and boom the iPhone camera activates within the app and it will show the nearest restaurants, bars, and anything with a Yelp rating. To date, this is one of the first iPhone apps to use this feature, which reportedly was not supposed to come out until iPhone 3.1. What could be better? How about a similar augmented reality feature for social networks such as Twitter or Facebook or where my cat likes to hide!