http://filehelpers.sourceforge.net/
Very cool, very nicely documented, looks very polished.
The first is the original that started things off:
It's lightbox v2, this one has fancy image transitions which can be used for a form of slide shows, and blends down the background.
A little harder on the eyes unfortunately but with it's own set of merits (more options, less overhead) is ibox.
This one can be used to show hidden layers with greyed out background as well as external html files and images.
A demo can be found here.
Both of these libraries are free.
2 Articles about Django from 2 different people:
Django: first impressions - overview with links
Django: first impressions - technical overview
The first one covers a lot of ground through it's links and is a pretty good starting point for Django.
The main upside of Django is that it gives you a very nice Admin interface with almost no work + it has a pretty nice template language.