Augmented Reality was not meant to hit the iPhone 3GS until at least the release of iPhone OS 3.1. Augmented reality uses your iPhone’s camera, GPS, and compass to show virtual items in the real world. Put your camera in front of a restaurant and it will come up with info, or use it to find nearby Twitter users. The potential is endless.
Yelp’s new iPhone app is now the first iPhone App with Augmented Reality. It takes Yelp information and overlays it into the real-world. It’s actually a secret easter egg (discovered by Robert Scoble), which may be why Apple didn’t reject Yelp’s augmented reality app.
Watch the video on this link on how to activate it on your iPhone: