Background: Upgrading site from Drupal 5 to 7. The D5 site used image module that came with a ready to use image gallery. We had hundreds of pictures. Each picture was associated with one taxonomy term (image gallery).
Use case: An image gallery grouped by taxonomy term and has the latest posted image (thumbnail) as the album cover. This image links to a page which is in a grid of thumbnails of images pertaining to a specific taxonomy term. Individual thumbnails link to individual nodes that may have one or multiple images per node that open in a colorbox. The node itself has images in a grid rather than default drupal vertical stacking of images.
Step 1: Create a Taxonomy Vocabulary: Image Gallery and add whatever terms to suite your image gallery.
Step 2: Create an Image content type with Title, Body, Image field and a Term Reference to the Image gallery vocabulary. Be sure to allow unlimited images for the image field or whatever you require.
Step 3: Display Image nodes as a grid of images:
You will require: EVA: Entity Views Attachment http://drupal.org/project/eva
Create a view: I called it Image node grid (or whatever)
Add-> EVA Field
Format: Grid | Settings (default)
Show: Fields | Settings (default)
Content: Image (your image field)