I've created an extension to embed SmoothGallery image galleries into MediaWiki articles via a parser extension. It should be a mostly feature complete integration of SmoothGallery. For more info on the extension, see:
http://www.mediawiki.org/wiki/Extension:SmoothGallery
SmoothGallery is a Javascript/CSS image gallery; for more info on SmoothGallery, and examples of galleries, see:
http://smoothgallery.jondesign.net/what
V/r,
Ryan Lane