Not exactly what your'e talking about but you should take a look at Word Lens(which google just bought). Basically you hold your phone up and position it over

Not exactly what your'e talking about but you should take a look at Word Lens(which google just bought). Basically you hold your phone up and position it over a piece of text using the camera. It then OCRs the text, translates it, and replaces it in realtime in the camera feed. It's pretty remarkable.