Google have just started another project, it is called Photovine. The idea behind it seems to be an adaptation based on Flickr’s tagging system.
Firstly someone takes a photo with their phone; let us say it was a picture of the sun. That person then tags the photo with a topic, such as “Yellow and Bright”. Afterwards other people can find that topic alongside the original photo. Now they can add to the topic by taking their own photo. This could be something such as a daffodil. This topic then develops and can grow over time. Finally a gallery is produced, it contains all of the pictures which are associated with that topic.
It is a really nice adaption, and I would like to see this develop further. It would be interesting to see how expansive some galleries become.