Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results. Look and feel of Select2 is based on the excellent Chosen library.
Best jQuery SelectBox Plugins & Tutorials with Demo
Auto-populating Select Boxes using jQuery & AJAX
If you are familiar with using select boxes for categorisation and sub-categories, such as ebay does when selling an item, usually this can require a lot of JavaScript to maintain the select boxes, but jQuery can hugely simplify this task by adding a dash of AJAX.Allow the user to select a top level category from one select box and to automatically populate the sub-category.
jQuery SelectBox Plugin
While it is possible to use CSS to style SELECT elements, browser support and appearance will vary greatly depending on platform and browser. In our search for a solid, customizable replacement for these finicky controls, we turned up only a handful of possible options that we ultimately weren’t thrilled with for one reason or another. Thus, today we’re introducing a new jQuery plugin that replaces standard SELECT elements so you can customize them entirely using CSS. We even threw in some extra features for added usability.
The plugin works by piggy-backing your existing SELECT controls. Since the original controls aren’t destroyed (they’re hidden), you can easily integrate this plugin into just about any existing form. The plugin degrades gracefully, as users without JavaScript will see the default SELECT controls.
jQuery Stylish Select
A cross-browser, accessible alternative to the standard form element which can be fully customised with CSS.Stylish Select attempts to replicate the functionality of the browser default select box as closely as possible with support for keyboard navigation, and intelligent positioning.
jQuery Stylish Select aims to have a minimal code footprint and weighs in at just over 3KB when minified.