Lightbox JS, Greased Lightbox & Tiddlywiki
there's also a greasemonkey script for Google Images and Flickr:
And I've been using Tiddlywiki to replace a couple of hundred text files hanging around my laptop - it's a wiki in one file:
Re: Lightbox JS, Greased Lightbox & Tiddlywiki
That is very, very cool. Been meaning to find a reason to use Greasemonkey. Also the standalone looks a very smart way to present images from a gallery, much better than a pop up or new page.