While it might not be much help to those on mobile devices, there is a “refresh” button on reCaptcha. If a word is too hard to make out, just refresh and you’re on your way.
I kind of like reCaptcha just because of what it does. You’re helping digitize books as the second word is always a word that an OCR had trouble digitizing. Which also means (I think) that you can practically ignore the second word.
-T
Edit: Correction, you can ignore the first word – I just put it “ttt” for a three letter word and got through. :-)