A couple of weeks back, I mentioned an idea about making video games adaptable to any urban environment. As a sort of footnote, I discussed another application:
Imagine being lost in a foreign city, taking a digital photo and plugging it into the PalmPilot. Software compares your photo to the city database, and tells you not only what corner you’re on, but what direction you’re facing.
As Slashdot reports, two researchers at the University of Cambridge are way ahead of me:
Roberto Cipolla and Duncan Robertson have developed a program that can match a photograph of a building to a database of images. The database contains a three-dimensional representation of the real-life street, so the software can work out where the user is standing to within one metre.
Never be lost again. Now, if we could just extend this to the whole planet. Of course, it’d be trickier in the wilderness, what with all of that stuff that grows, dies and falls over. Of course, as one Slashdotter puts it, this sounds like a solution in search of a problem. We’ve already got GPS devices that can find you. Mind you, if your cell phone isn’t GPS-equipped (and whose is?), then this means one less device to carry around.
DarrenBarefoot.com 
How about an easier solution, GPS? Hook in your phone to a GPS reciever, use the phone’s screen to show you accurate, down to the meter maps of where you are. It’d even work if you’re in the middle of the desert with nothing but sand to photograph.
I think it’s a neat idea, but still seems that it might be solving a problem that doesn’t really exist. I’m sure that photo recognition for buildings or some similar technology *does* have good use though.
put a compass on your key chain and find a street sign.
not knowing where one is? That is most def. a problem that exists.