What is ModalBox?
ModalBox is a JavaScript technique for creating modern (Web 2.0-style) modal dialogs or even wizards (sequences of dialogs) without using conventional popups and page reloads. It’s inspired by Mac OS X modal dialogs. And yes, it may also be useful for showing larger versions of images. 
ModalBox is built with pure JavaScript and is based on Sam Stephenson’s excellent Prototype JavaScript Framework, script.aculo.us and valid XHTML/CSS. ModalBox uses AJAX to load content.
ModalBox technique is still in development. Please feel free to comment or submit your bugs here: http://code.google.com/p/modalbox/
Sources of inspiration
Basically, ModalBox is based on GrayBox technique by Amir Salihefendic. But you can find a lot of similar techniques around the web: Lightbox JS, Lightbox gone wild, ThickBox etc.
There also a clone of ModalBox, the MOOdalBox, written on the great and lightweight Mootools Framework.
Links
Nice and simple I l ike it!