Point-and-scan character Id for mobiles

This probably exists, but i don’t know what it’s called. Thinking along the lines of a app for a mobile that scans the character(s) you want to Id (in this case, they’re on an unidentified tin in the garage). So you take a ‘pic’ of the characters, and the phone app then recognizes them for you.

My option right now is to take tin inside, then look up in dictionary, or hand-write into Nciku.

Can think of loads of occasions/places where this would help me out.