Yasg is short for Yet Another Simple Gallery. It cannot get any simpler than that - imho.
Yasg is a Gallery plugin that uses the WordPress built in gallery extension and displays it as a set of thumbnails and a main image. Clicking a thumbnail displays it as the main image. This gallery doesn't use Lighbox, but it can be added easily by adding a link and a 'lightbox' class to the main image (Providing off-course having downloaded and activated the 'lightbox' plugin). Important Notice: The name of the plugin directory was changed from yasg to yet-another-simple-gallery when it was created in the plugin's repository. That made all paths to scripts, css and images to break. :-(. If the plugin doesn't work for you, please remove it and download it again. This should fix the problem. I am terribly sorry for this mishap.
Major new features in YASG 1.1 include: