Xml photo gallery

hello…
there was a tutorial recently posted on a modified xml photo gallery in which the thumbnails of the images were done in a scroll manner. In that tutorial as well there was another option where the thumbnails were just placed in a set grid…however, the tutorial for that wasn’t given. Anybody out there know how to do modify it so that the thumbnails are just laid out in a preset grid of 3 images by 3-4 images? Any help will be much appreciated. Thanks!