The image transition manager is a javascript library based on scriptaculous and prototype. It supports several image transitions, such as fading, appearing, sliding, growing and shrinking. Because it uses the unobtrusive javascript technique, no inline javascript is needed and hyperlinks still function when javascript is disabled.

I think the script works really great, you can have 8 (more to come) image transition effects to spice up your site. However, I found it a bit slow to load the image first time. It would be much better if the script preloads all the images beforehand.

Requirements: Scriptaculous 1.7.3 beta and Prototypejs 1.5.1.1 Framwork
Demo: http://ajaxorized.com/image-transition-manager/
License: License Free