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 Dialog

Displays customizable dialog windows.

jQuery UI Transfer Effect

Displays a transfer effect from one element to another.

jQuery UI Tooltip

Shows additional information for any element on hover or focus.

jQuery UI Clip Effect

Clips the element on and off like an old TV.

jQuery UI Scale Effect

Grows or shrinks an element and its content. Restores an elemnt to its original size.

jQuery UI Sortable

Enables items in a list to be sorted using the mouse.

jQuery UI Drop Effect

Moves an element in one direction and hides it at the same time.

jQuery UI Menu

Creates nestable menus.