Easily assign categories to media with a clean, simple, and searchable category meta box. Then use the gallery shortcode to display category galleries
This plugin will include clean, simple to use, searchable categories to your Media Editor page.
Use categories in much the same way you use them on your posts and pages.
Filter categories as you type, very useful if you have a lot of categories to look through (thanks to Jason Corradino's "Searchable Categories" plugin)