The Flickr User Model
Designed by Soldier Ant (his real name is Bryce Glass), the Flickr User Model attempts to map out the Flickr user experience. This is version 0.1, and I think he's working on version 0.3 now. Also linked on visualcomplexity.com
On his post on October 24, 2005, Bryce explains: "I've been doing some concept diagramming for work lately, and I've found myself enjoying it immensely. (...) However, since it's for work I can't share much of it. I did post some sanitized versions, with all the object-names obsfucated, but that just didn't seem wholly satisfying. So over the weekend I invested some time in a diagram that I can share with the internets: a simple Flickr user model (regrettably incomplete -- but I realized that if I tried to include the whole Flickr-verse that this diagram would go beyond labor of love and straight into excercise in folly)".
Thanks Rex for sending in the link!