I'd be curious to see the ability for a machine to solve picture based captcha systems. For example, given a lineup of 10 pictures of pets, choose the three that are cats. I've seen them before, just not widely implemented.
That is the primary reason why I believe that people who use the term 'computationally unfeasible' (you see that a lot in crypto papers) never counted on the kinds of growth we've seen in computers coupled with the ease with which these folks can steal computer power from clueless users.
My claim is that you need an independent engine of computation on your side that can prove you are you with a high degree of confidence, and cannot be corrupted economically by a third party. (so local programs on your PC or Smart phone won't cut it)
Of course that doesn't apply here.