According to Media Culpa a blog that apparently obsessively tracks these things, photo-sharing site Flickr has hit the 5 billionth photo milestone today with the above, uploaded by Flickr user yeoaaron. Media culpa blogger Hans Kullin also points out that Flickr has been growing at about 1 billion photos per year, over the past 3 years, eclipsed in market share by social giant Facebook which hit 15 billion photos uploaded in April of 2009.

techcrunch.com/2010/09/18/flickr-5-billionth-photo/