Sly is a jQuery plugin for one-directional scrolling simulation with item based navigation support and lots of other goodies.
jq-tiles is a slideshow with many cool css3 effects.
In browsers that don't support css3 transitions classes won't be animated but some effects will still work.
PFold is a very experimental jQuery plugin that makes it possible to open elements in a paper-like unfolding effect. An element can be unfolded in 3D in order to reveal some other content. The idea is to have several levels of folding, where each step of opening will double the element size, hence imitating a folded paper being opened.
Windy is a jQuery plugin that allows a rapid navigation through a pile of items using some CSS 3D transforms and transitions. The effect of a continuous navigation flow reminds of a deck of cards or sheets flying away, hence the name.
Form Accordion is a jQuery plugin for easily hiding and revealing related form fields conditionally.
slideControl.js plugin allows you to create nifty slider controls for text inputs.