"Any sufficiently advanced technology is indistinguishable from magic." - Arthur C. Clarke
Quest Visual's Word Lens (free) is a revolutionary augmented-reality app for iOS that instantly translates printed text in photos by using the iPhone's built-in camera, in real-time -- like magic. Simply point your iPhone at a sign, package or menu and Word Lens translates it into another language, on-the-fly. It's one of those apps that you know is special the first time you see it (like StarWalk, Pulse, FlipBoard and their ilk).
Quest Visual makes its money by selling language packs for Word Lens as in-app purchases. Spanish to English and English to Spanish language packs are available for $4.99 each. If you don't want to pony up the $5 for the paid language packs, check out the reverse words feature in the free version. It's freaky watching the words change in front of your eyes in real time and it gives you a taste of how the technology works.
As you could probably guess, it doesn't work well with handwriting, stylized fonts, type on a curve or pretty much anything other than stock helvetica. Luckily most of the signs in the world use helvetica anyway, so this app has a ton of potential. It has the potential to be a truly disruptive technology.
Download it now and encourage the developer to create new language packs.