Recently, I designed, themed and developed a new site for my photography, High Rock Photo. The obvious choice for this new site was to use Drupal 7. I wanted the ability to easily create node galleries and this screencast shows you how to create and theme a node photo gallery using Drupal 7. I will also point out what modules are needed and make reference to those that would have been used in Drupal 6 and are now integrated into core in Drupal 7. You will also find some custom template code published that I mention in the video for your theming.
Template Code (Drupal 7)
field--field_gallery_photo.tpl.php » /sites/all/themes/[your_theme]/templates/ -- note the name of this file is dependent on the specific name of your field!