Via Gizmodo, I came across these estimates on 1000 memories about the number of digital photos in existence:

Digital cameras are now ubiquitous – it is estimated that 2.5 billion people in the world today have a digital camera[6]. If the average person snaps 150 photos this year that would be a staggering 375 billion photos…. Every 2 minutes today we snap as many photos as the whole of humanity took in the 1800s. In fact, ten percent of all the photos we have were taken in the past 12 months.

I'm often more than a little skeptical of these comparisons of content creation or consumption today versus in the past– how do you estimate how much information was generated in 1600, and can you really use the same metrics to measure how much information there is in an issue of the LA Times or Wall Street Journal?– but photographs seem more easily comparable between analog and digital realms.

There post also reports the great statistic that in 1960, 55% of all photos were of babies.