Marble has a plugin for rendering flickr photos on top of the map. It should be extended to have a configuration dialog where the user has the option to choose which licenses he accepts. For each license supported by flickr, one checkbox should store whether Marble will download such photos.

• http://www.flickr.com/services/api/flickr.photos.licenses.getInfo.html shows you the ids and names of the licenses flickr supports
• Adding the line
  options.insert("license","1,3,5");
  to PhotoPluginModel.cpp in the getAdditionalItems() would tell Marble's photo plugin to restrict flickr photos to those licensed by the respective licenses (the numbers are the flickr ids)
• Create a suitable dialog with the needed seven checkboxes and set the options correctly to calculate the string based on the user choice.
• The task http://www.google-melange.com/gci/task/view/google/gci2012/8076212 needs to be implemented as a prerequisite for this task

See also http://marble.kde.org/contributors-welcome.php and http://marble.kde.org/sources.php