Sure, you can do smart things with DHTML. But it is browser dependent.
A library of nice looking DHTML scripts. Includes section with AJAX examples.
Good introduction to using XMLHttpRequest.
XMLHttpRequest is becoming more and more popular, and many people are currently exploring what we could do with it. Unfortunately this also causes people to reinvent old and forgotten usability problems.
Greasemonkey is a Firefox extension which lets you to add bits of DHTML (user scripts) to any web page to change its behavior.
The cross-browser rich-text editor implements the Mozilla Rich Text Editing API included with Mozilla 1.3 . There is NO LICENSE, so just take the code and use it for any purpose. This code is 100% free. Enjoy!
The Dynamic Standard, dhtml scripts and tutorials.
Some links from Sam-I-Am.
IE 5.5 exclusive, but nice features with Page Zooms and such.
Articles, tutorials, and much more.
In a hurry for some DHTML? Try our new drive-through script builder, the DHTML Dynomat! The Dynomat makes the process of generating the more complex scripts from DHTML Lab columns automatic.
Learn to use MS DHTML with CSS here!