Vanilla JavaScript Plugin  

A sophisticated select input field with lots of customization options.

Plugin Website  Demo

Related plugins

Stretchy Form Element Autosizing  

Auto-resize textareas, input fields and select boxes on update.

BunnyJS Form Validation  

A plugin for smart form and input field validation.

Component Picker  

An iPhone-style form field widget that can be used to select dates or whatever you pass into it.