Scrollovers

Scrollovers are a way to quickly and easily add flair to your web pages, giving your users an experience they weren't expecting.

Integration of Scrollovers into your web site couldn't be easier, even if you’ve already built the site that you want to include Scrollovers on. In just minutes you will be able to have them appearing on your own pages.

Link:
http://www.scrollovers.com/