Chosen

Chosen is a JavaScript plugin that makes long, unwieldy select boxes much more user-friendly. It is currently available in both jQuery and Prototype flavors.

jQuery File Upload – jQuery UI version

File Upload widget with multiple file selection, drag&drop support, progress bars and preview images for jQuery. Supports cross-domain, chunked and resumable file uploads and client-side image resizing. Works with any server-side platform (PHP, Python, Ruby on Rails, Java, Node.js, Go etc.) that supports standard HTML form file uploads.

jQuery UI Droppable

Enables drop targets for draggable elements.

jQuery UI Shake Effect

Shakes an element horizontally or vertically n times.

jQuery UI Button

Enhances a form with themeable buttons.

jQuery UI Slide Effect

Slides an element in and out of the viewport.

jQuery UI Puff Effect

Creates a puff effect by scaling the element up and hiding it at the same time.

jQuery UI Tabs

Transforms a set of container elements into a tab structure.

jQuery UI Dialog

Displays customizable dialog windows.