IE6+ incorporates a new feature called MyImage Toolbar, which, if enabled on Tools,Internet Options http://www.codefoot.com/javascript/script_myimage_toolbar.html
Learn about IEs improved Fade filter, and see how to use it to easily create a cross browser image slideshow http://www.javascriptkit.com/howto/showie4.shtml
Change images on mouse over with javascript. Define the images and preload them. http://www.999tutorials.com/tutorial-change-images-with-javascript.htm...
If you have a page that takes long time to display it is a good idea to display a wait until the page loads image. http://www.reconn.us/content/view/37/47/
Create a system that rotates specific banners automatically without the need of the page being refreshed http://www.tutorialcode.com/javascript/rotating-banners/
Image Thumbnail Viewer is a compact, unobtrusive image viewer that can be applied to any link on the page http://www.dynamicdrive.com/dynamicindex4/thumbnail.htm
Learn how to use a JavaScript trick that makes PNG alpha transparency work in Internet Explorer http://www.devpub.com/making-png-images-transparent-in-ie6-t2.html