Create custom transparent corners and borders using JavaScript and CSS. JSON - plug this script in without worrying about it conflicting with other scripts.

Create cross fading content boxes using DHTML and JavaScript. No need for heavy Flash.

Create dynamic web page designs which change based on the width of a readers browser window. Browser window windows dictate which stylesheet is applied to a page.

Create super clean and simple bar graphs with CSS. No images required. Progress is controlled using width:xxpx within the progress container.

Create a framed layout - fixed header and footer - using CSS. Support for all major browsers including IE5/IE6, Opera, Omni, Safari, and Mozilla.

Implement tabs on your page using CSS, a little JS, and semantic markup which degrades gracefully. Supports multiple (nested, even) tabsets on the same page and allows users to bookmark the page loading to a specific tab.

Until Microsoft gets their act together with their Internet Explorer offering, the last resort web developers have is a little bit of Javascript trickery. Dean Edwards has just the trick. Preload this script and code with web standards in mind - no worry.

Visualize the structure of an XHTML document by adding a colored outline around the border of every element. Add these lines to your stylesheet in order to view the structure hierarchy.

Create nested navigation menus. Great samples of the possibilities. Use these to cut back on multiple nav bar options within a single page.