You know how credit is never given in an ad? Well, no more. The above print ad from Virgin Mobile gives credit to the photographer, which is especially nice since Virgin did not pay for the image. Their agency found it on Flickr and published it under a Creative Commons license.
While this is an interesting idea, there are a few problems with it. One, neither the models nor the phtotographers were contacted, thus no consent was expressly given. As far as the photographer goes, it may be okay since their rights are detailed under the Creative Commons license that they themselves chose to use. But the subjects in the photos are another story.
Here’s the Flickr discussion string on the subject.