The organize module comes as a part of the core suite of modules in galley 3 allowing you to move and reorganise the order of pictures within an album, between albums and the order of the albums themselves.
To use this module, go to "Album Options" and select the option "Organise Album". Once you are in the organise album view you will find the automated ordering options at the bottom of the window. To manually order the photo's drag and drop, or move in between albums to the left. To organise the top level of albums go to the top of the left album listing. Here you can then organise your gallery. Any photo with a yellow folder in the bottom left is the title photo of an album.