I actually really liked the scrolling effect on this website.
7 karma · joined January 17, 2013
One approach that I enjoyed seeing was the use of reverse captchas. Here you pose a problem that a computer can easily solve, but a human cannot. For instance, if you ask a simple question (1+1=?), but you place the question box off the screen so the user can't see it. A computer would be able to easily answer the question, but a human user would have no way of doing so.