Simple Galleria for WordPress is a jQuery image gallery based on WordPress native galleries.
You just need to put [gallery] inside your content. More info here http://codex.wordpress.org/Gallery_Shortcode
I had to remove Fancybox from this plugin because the 2.0 version of this library is no longer under the GPL Licence. I had to use jQuery Colorbox instead which is similar. If you need to go back to the previous version, please visit my blog at this page: http://benjamin-niess.fr/where-is-my-simple-galleria-for-wordpress-plugin/
Create your translation file from the sgfw-default.po one and replace "default" by your country code (eg. sgfw-us_US.po) Paste the po and mo file into your wp-content/languages/plugins/ folder