Litebox
Litebox is a modified version of Lightbox v2.0 created with one thing in mind, size reduction. Litebox utilizes the 3kb javascript library moo.fx in association with prototype.lite, giving us the basic tools we need to make this work and you the ability to expand.
Support: Images, Image Sets
Leightbox
I’ve changed ParticleTree’s lightbox functionality to allow the use of inline div’s instead of AJAX calls. Very often I find that I want the data in the lightbox to be indexable by search engines and visible to people with screenreaders etc. This adaptation makes that possible. Mind you, i’ve completely removed the AJAX calls.
Support: HTML, Text
Lightbox 2
Lightbox is a simple, unobtrusive script used to overlay images on the current page. It’s a snap to setup and works on all modern browsers.
Support: Images, Image Sets
Lightview
Lightview was built to change the way you overlay content on a website.
It is Clean: Designed to compliment your content., Fast: Smart image preloading.Easy to customize: You don’t even have to know CSS.Rounded: Adjustable rounded corners, without PNGs.Smart resizing: Content will always fit on your screen. Custom events: Using Prototype 1.6 Slideshow: One button slideshow.
Effects: Using Scriptaculous.
Works on all modern browsers.
Support: Images, Image Sets, iframes, HTML, Ajax, Flash
Lightwindow
Supports EVERY Media type and renders it appropriatly., Better Animations!, All video/media bugs have been resolved!, Major improvements to IE!, Create your own custom overlays including transparent patterns!, You can create your own theme including markup/css/animations, author, caption, title, and params (Added for this library) attributes are supported, Create a window on the fly! and lot more…
Support: Images, Image Sets, iframes, HTML, Ajax, Flash
Lytebox V3.2
Since the original version of Lytebox (which released with iFrame support), major modifications have been made to improve performance as well as “Slideshow” support, “Themes” support, HTML content support (as opposed to just images) and many more configurable options that allow you to customize the look and feel of Lytebox. These modifications were added as a result of user input, so if you feel you have a good idea for a new feature, then visit the Lytebox Message Boards and let it be known!
Support: Images, Image Sets, iframes, HTML
Lightwindow
Lightbox JS is very cool and useful script to display an image on the page.
However only the part of the image is displayed when the image size is larger than the window size. So I’ve created a script based on Lightbox JS.
Support: Images, Image Sets
iBox
iBox is a lightweight script that lets you overlay images and documents in a small dialog without a page reload. It’s built to be easy to install and use, while offering great flexibility. The quick start shows example code and explains how to use it.
Support: Images, Image Sets, iframes, HTML, Ajax, Video
GreyBox
GreyBox can be used to display websites, images and other content in a beautiful way. GreyBox can be used to display websites, images and other content in a beautiful way.
Support: Images, Image Sets, iframes, HTML
Highslide JS
Highslide JS is an open source JavaScript software, offering a Web 2.0 approach to popup windows. It streamlines the use of thumbnail images and HTML popups on web pages. The library offers these features and advantages:
Support: Images, Image Sets, iframes, HTML, Ajax, Flash
SWFbox
The flash content is centered horizontally and vertically, You can have more than one SWFboxes in one web page, It’s lightweight. The code is simple and tight and includes only what is needed, Easy to implement. You only need to write the code for the link and the pop-up is generated dynamically.
Support: Flash
ThickBox
ThickBox is a webpage UI dialog widget written in JavaScript on top of the jQuery library. Its function is to show a single image, multiple images, inline content, iframed content, or content served through AJAX in a hybrid modal.
Support: Images, Image Sets, iframes, HTML, Ajax
TinyBox
TinyBox is an easy to use lightweight JavaScript library for creating modal windows/dialogs in an elegant manner, without using traditional pop-up windows. It can be used to overlay content on the current page.
Support: Ajax
WeebBox
This is a modified version based on Lokesh Dhakar’s superb orginal lightbox that (i think) simplifies some of the features, adds some config options, moves the nav to the top and best of all incorporates a slideshow feature so you can sit back and watch your pics with a single click!
Support:Images, Image Sets
FancyBox
Why? Because I was bored by so many pages using lightbox and it`s clones,
I wanted something fresh and Mac-like. I couldn`t find any cool alternative that would be build on top of jQuery, so the FancyBox was born.
Support: Images, Image Sets, iframes, HTML
ShadowBox
Shadowbox is an online media viewer application that supports all of the web’s most popular media publishing formats. Shadowbox is written entirely in JavaScript and CSS and is highly customizable. Using Shadowbox, website authors can showcase a wide assortment of media in all major browsers without navigating users away from the linking page.

Wow! I didn’t realise there were so many options! Thanks for compiling the list. Tinybox looks like it might be of interest to me personally. I’ll spend some time fiddling with all the different choices now!
Joe - http://www.anewbandaday.com