Acrylian, I think we just hit upon a snag keeping a Drupal / Zenphoto bridge from happening. You aren't familiar with Drupal, and Drupal developers aren't familiar with Zenphoto. And both offer only partial substitutes for the other's features. Don't get me wrong, I love Zenpage, but it's fairly limited as a CMS. And I love Drupal, but creating image galleries in it is cumbersome at best.
Currently the best gallery support for Drupal is either Gallery, which is far too complex, or Drupal's own image solution which requires individual uploads of every image.
The amazing simplicity of Zenphoto would be a powerful complement to Drupal's powerful content management system.
I will look into the Zenphoto as plugin solution.