MiniAjax.com: Showroom for DHTML and AJAX scripts
There is a lot of good stuff to explore here such as:
- GreyBox - a simple window you can use to launch another webpage within your website
- Reflection.js - create cool image reflection effects
- Heatmap - a hot (pun intended) utility to let you see where users click on your website
- AjaxIM - a browser based IM client.
- and many many more.