After reading a tweet from Marco Raaphorst about his most popular photo on flickr, I checked the stats for my most popular photo. Delving into more stats, I realised I had posted one youtube video (post) and lo and behold! This video is most popular amongst men (well boys, really!) of the ages 13-17.
(I should probably add that the video is a short piece of a Julie Andrews concert: not really the right focus group!)