I was meaning to use the idiom "to boot", you cut off a word. Perhaps my grammar wasn't correct there though. In any case, check out the blackhat presentation

I was meaning to use the idiom "to boot", you cut off a word. Perhaps my grammar wasn't correct there though. In any case, check out the blackhat presentation about using Google's image recognition to solve the image based captchas. There are a wide variety of fairly advanced image recognition tools but a surprisingly small number of complex text recognition ones.