These are exciting days to IPhone Applications. The API to Augmented Reality support in IPhone it will be released with the next version of the IPhone Operating System. But there are some applicactions now using the new features.
One (possible the first) application is the Paris Metro Subway app:
Yesterday, Robert Scolbe discovered an Augmented Reality easter egg in the new Yelp applicacion. According to:
Social review service Yelp has snuck the first Augmented Reality (AR) iPhone app specifically for the US into the iTunes App Store. The undisclosed new feature allows iPhone 3Gs owners to shake their phones three times to turn on a view called "the Monocle." This view uses the phone’s GPS and compass to display markers for restaurants, bars and other nearby businesses on top of the camera’s view.
Robert Scoble FriendFeed pub: http://friendfeed.com/scobleizer/e6e411b4/new-yelp-iphone-app-is-also-out-there-cool-easter
Download the new Yelp app (came out yesterday). So you shake your iPhone 3 times. That activates a feature called Monocle. A message should come up if you activated it. A blue box will come up saying "the Monocle has been activated." It will create a button in the top right corner. Now you should be able to look at the bars, restaurants, etc. Only works on iPhone 3GS. –
More info at: