Thanks to a tip from Lise, I found a new cool image javascript effect, called Shutter Reloaded. This effect you can download as WordPress plugin here : http://www.laptoptips.ca/projects/wp-shutter-reloaded/
It’s a very lightweight (5kb) and easy to use script and looks very cool in my opinion. If you would like to use it , then simply download the plugin and activate in the shutter reloaded settings the option : “Shutter on all image links and use LightBox style (rel=”lightbox[…]”) activation and sets.” Now select in the NextGEN Gallery options->effect the “Lightbox” effect code…
See it live in action at my random pictures…