I just used this site, and learned that 18-34-year-old women find a picture of me without a baby more attractive, while the 50+ demographic definitely prefers the picture of me holding my niece. Biologial clocks at work? Anyway, worth $5! ;) Well, sort of... I wish there was a way to view the votes by (gender,age-group) pair, but most of the respondents were female, so I think I'm interpreting the results correctly.
Also, I just emailed a friend about this and shared the PickFu URL for the results of my photo survey on facebook, which according to Derek Sivers is a great sign (http://sivers.org/purplecow).
Finally, note that you can see all the PickFu questions as they are distributed to Mechanical Turk (even the "private" ones, obviously) at
https://www.mturk.com/mturk/searchbar?requesterId=AI2HRFAYYS...
I hope your site can scale. I predict growth.