Unfortunately Lightbox2 is not available for Drupal 7 now. There is a beta, but that dosn't work for me.
Due to a hint from brodiebrodie i get knowledge of the module Colorbox. Because it is relativly simply to implement is decide to do it ;-)
If Colorbox is enabled, himuesgallery will use it automatically.
I decide to implement the neccessary JavaScript-code in himuesgallery.tpl.php.
If you want to theme a module, this is the file in wich you do it. If you want to set other parameters for colorbox, then you can do it in the same place.
#813370 by myself, sun: add support for parsing hook_menu_alter() and a different array syntax in hook_menu() for those prefering that (in some cases); also fixed tests so they can be run on Drupal 7, and validated tht they still pass
#1039398 by myself: reorganize code to support context on st() and $t() like core does already