This library has some well-done DHTML animation effects. Crashes Opera in Linux, but it’s cool nonetheless. You know what else is cool? Buttons 
FACE: Faruk’s Animated CSS Enhancements – KuraFire Network
For the longest time, the Web has existed as a static medium, where only animated GIFs and, later on, Flash added some life to pages. With the advent of web standards and DOM scripting, people have started to look more and more at Javascript to add interactivity to websites.
With FACE, a new technology by Tim Hofman and myself, this process has been made so simple that anyone can make their websites come to life, without having to know a whiff of Javascript.