Photobox is a module for joomla 1.5, joomla 1.6, joomla 1.7 and joomla 2.5 that displays photos in a popup photo show window. This is a module and plugin. After installing you should unable the plugin in able to work. In the module is the option to load photos from an folder in your site, any module, flash file or html code in a popup window. Check the demo here.