First up was the Paris Subway augmented reality iPhone app, then came the London one, and now the U.S. version has hit the iTunes App Store. Borrowing from sci-fi movie implementations of the idea, it has been rebranded the Bionic eye.
It works just like previous versions--using the GPS and digital compass of the iPhone 3GS, it superimposes geotagged information over the camera's video feed. That helps direct users to the nearest subway stations, restaurants, fast food joints (which probably won't be all that far away), and so on. Best, it can show you nearby Wi-Fi hotspots, even though the system doesn't use data over Wi-Fi or 3G broadband (points of interest are pre-loaded).
The app's out now in the iTunes store for a single dollar, and an in-app micropayment will add coverage for New York, Washington, or Chicago. As neat as it is, it's just a taste of the amazing iPhone AR apps we'll see in the next year.