Métro Paris, an iPhone app [see also the FastCompany article] to help us navigate the Paris subway has been beefed up to include heads-up displays that allow you to see pop-up displays of information about the buildings and businesses around you. You turn on the app and it shows you what your camera is seeing (vélos, motos, voitures moving along the street, and buildings) and rectangular squares pop up that tell you what the buildings and businesses are. In addition, you can get a big red arrow (like in SecondLife when you’ve teleported close to your destination but still have to fly to get there) that points you at a nearby Métro station that you can duck into to take the train to your destination. These augmented reality apps [see article on LA Times site] have been rumored to be on the way for quite some time. Apparently the heads-up portion was sneaked (snuck) into the app without Apple pretty much noticing that it was there. Thus the speculation about whether it‘ll be taken down. The photos/videos tell the story – take a look. [SEE VIDEO BELOW vids are in French – the demo is at Place de L’Opéra – I know it well.]
The talk about Apple taking down this app appears to be related to the stress it puts on the iPhone and/or that the 3.0 software toolset (the “API”) in the phone itself isn’t really ready to support this app. They say it won’t be available until 3.1 is released. (Does this mean it’ll run on my regular 3G iPhone?) It is a great step forward! And definitely visonary.
Métro Paris is available from the Apple iTunes/iPhone store now. Did I say it only works in Paris?
 A heads-up display is one where you don’t have to move/tilt your head in order to see some screen – you just look at the real world and a glass panel, or other device right in front of your face, allows you to see a display that mixes the real world with additional information. I doubt there’s any photo-recognition built into this app – instead I’d guess that it takes the GPS readings and the motion sensors and “knows” which direction you‘re looking, and then just superimposes the correct information on the photo rather than recognizing the buildings – too hard a task for a small CPU.
 Augmented reality extends the “real” experience with the phone by adding (in this case) visuals that provide additional information.