My pal Robert Scoble announced that the Yelp iPhone and iPod touch app that was recently updated included a hidden Augmented Reality feature. Obviously, as soon as we saw, we had to give it a shot, and we figured we’d do it on video. Augmented Reality apps use the camera on the iPhone, along with overlaid information, to present location data while looking at the “real world” - it’s very cool, and you can expect a bunch more of these types of apps to make an appearance on the App Store very shortly upon the release of iPhone OS 3.1.

In this demo, we show you how to unlock the Monocle mode in the Yelp app, and also give you a look at what exactly it does. For now, our early opinion is that it’s a cool idea…it just needs to be refined a bit to be truly useful.