From the Code: Flickr Developer Blog.
Over the weekend we broke the Hundred Million geotagged photos, actually 100,868,302 at last count, mark. If we remember that we passed the 3 billion photos recently and round the figure down a little that means does calculations on fingers that around 3.333% of photos have geo data, or one in every 30 photos that get uploaded.
In the last two and a half years there have been roughly as many geotagged photos as the total photos upload to Flickr in its first two years of existence.
Thanks to Brian for the link.