Convert your old Drupal site to Blogofile the lazy way! Run both at the same time and migrate at your own pace.
The photo gallery you've wanted with features like nested albums, Markdown captions for everything, autogenerated thumbnails, navigation breadcrumbs, and Disqus comments. See an example online at http://honeypot.net/pictures/ .
Both scripts are heavily commented to explain installation and usage.
These scripts are released under the MIT license, in the same spirit as Blogofile's own license as explained at http://www.blogofile.com/LICENSE.html .