Flickr, the photo sharing site owned by Yahoo, announced today that it has uploaded its 6 billionth photo.

“Over the last 5 years uploads have been increasing 20% year-over-year and we love hitting a milestone like this,” says Flickr’s Kay Kremerskothen. “It’s the ability to wander through the titles, tags, geotags, camera info, groups, comments, favs, and everything else associated with the photos that make the huge collection of photos on Flickr so unique. The more photos you upload, the more we all can explore.”

Here’s the six billionth photo. It is a nice one.

It was uploaded by user eon60 on Monday. I’m not sure why they waited until today to announce it.

6 billion is a lot of photos, and may seem impressive until you realize that Flickr’s been around since 2004. There’s an infographic from Pixable going around that claims Facebook is expected to have 100 billion photos by the end of the summer.

Not to turn the discussion away from Flickr and Yahoo, but I recently talked about how Google+ has made Picasa Web Albums cool again. If Google gets Instant Upload on the iPhone version, and keeps the growth of Google+ going strong, it will be interesting to see how it competes with Facebook in the photos category moving forward.