An ajax widget/ service that helps you see how people find, navigate and value the pages of your web site.
A script that turns content blocks on your page into tab blocks.
Some nicely numbered lists using dl, dt and dd tags inside a ol li structure.
Observation: Google's BigDaddy bot seems to be using a Mozilla-like crawler to decipher CSS and JS on your page!
A CSS based, cross browser zoom effect. Move your mouse anywhere over an image to enlarge that portion of it.
An excellent color picker script based on the new Yahoo User Interface Library.