Ender-overlay is a highly configurable overlay plugin for Ender. It requires Jeesh and Morpheus for animations. Even though, you can leave Morpheus out if you are fine without animations. You can easily build your own gallery or other overlay based logic on the top of this plugin.
Currently it's in a pre-alpha state, please do not use it in a production environment! Check back for stable builds. Currently it's tested in Chrome, Firefox, Safari and Opera. I'm going to add IE7+ support soon.
More information, documentation, demos: http://nemeseri.com/ender-overlay/