A new fad showing up among smartphone users is “Augmented Reality”; think of it as the way The Terminator sees the world. You look at something and all its stats flash into view, allowing you steal the right sized clothes off their owner, hotwire a motorcycle, and hunt down John Connor.
Unfortunately reality isn’t as cool or as useful. Right now we can take a phone with a camera and depending where you face it will overlay what subway stations are in that direction. Using location software like Google Latitude to map where friends are it would be possible to overlay the location of your friends like this too (except Latitude doesn’t work in the background so you have to kill it to see others, if they do the same nobody can see each other).
There are problems in reality us techies tend to ignore that stop this from being a true “killer app” and instead just a gimmick.
Current software isn’t really giving you anything you can’t get more accurately with an overhead map view. To simulate distance the sign is either at the top of the screen or the bottom rather than close or fading in the distance. Plus the subway that you’re heading to may be in that direction but it doesn’t take into account what is in between; so you may end up getting lost even more by making a bee line to the location rather than taking the correct streets to route around buildings, canals, and major uncrossable roads that could easily be seen and routed around with traditional navigation software. Imagine a metropolis like Tokyo with tons of maze like dead-ends where you can end up right next to the subway, but have a giant building blocking you from the entrance.
Overlaying a signpost in the direction of an object is cool but not really useful compared to existing tech, plus it’s processor intensive for the visual representation which leads to lag in displaying the info accurately. More intriguing is the ability to see an object or person, and download meta-data from the internet about them. However the only deployments of this have been too complex to work outside of demonstration.
It is cool stuff that will hopefully mature into something incredibly useful (like Terminator vision) but for now it’s just a gimmick with no real world value.
More info, and a more favorable view at Ars.