Following the release of Layar on Android smartphones here comes Metro Paris a french application ($0,79 and works in English too) which used augmented reality to help find POIs and train stations is the french capital. Similar to Layyr it uses the digital compass (and GPS) on the iPhone 3GS when you point your phone in a direction and displays POIs icons and arrows overlaid in the camera viewfinder. The app also works on non 3GS iPhones but the AR part is disabled due to the lack of compass. The application also supports Push notifications. Check this video demo:
Source: MetroParis on iTunes