Anyone tried auto cracking these? Doing a little research on it at the mo and wondering if someone has tried/succeeded in it.

Well, you won't find anything that's 100% accurate, but I know JDownloader features some experimental code to decipher recaptchas. And according to this article, some guy managed to crack it with about 30% accuracy.

Yeah, Jdownloader uses some stuff and it seems to work pretty good.
They basically break down the captcha's into the background, the letters and the scrambling (like lines, etc.).
I guess they use it to get the letters only (basically subtracting the background and the scramble. I don't know the right word for this technique) and then use some ocr or whatever...

if you're interested in writing your own, here's a video from defcon 18:

http://www.youtube.com/watch?v=dLgvrsAoPeE

Thanks for the responses, ill stick with the manual way for now

P.S very nice video !

Afaik you don't even need to be 100% correct to pass reCaptcha test either

well, you're half-way right. recaptcha uses two words - one real word and one fake word. the real word is the control, and you need to get that one correct. the other "fake" word has some lenience, but not much. you have to get it at least "almost right".