SelectAutocomplter is a plugin for MooTools (1.2) and Prototype (1.6) (see branches) that provides a way to create an editable <select>.  It works by replacing a <select> in your document with a text field that uses the Quicksilver filtering algorithm to narrow down results.
- User lists
 - Company lists
 - Dropdowns with many items
 
The Javascript is 100% unobtrusive and will fall back to a <select> tag for users without Javascript enabled. It's keyboard accessible and will respond to up/down arrow and enter/return keys as expected.
To activate the control, call new SelectAutocompleter(element, options) on any <select> tag you would like to replace.  Your server will receive the same response as if the <select> was not replaced, so no backend work is needed.
Any class names on the <select> element will be carried over to the <input> that replaces it as well as the <ul> containing the results.
- cutoffScore - A decimal between 0 and 1 determining what Quicksilver score to cut off results for. Default is 0.1. Use higher values to show more relevant, but less results.
 - template - A string describing the template for the drop down list item. Default variables available: rawText, highlightedText. Default value is "{highlightedText}" Use in conjunction with templateAttributes to build rich autocomplete lists.
 - templateAttributes - An array of attributes on the 
<option>element SelectAutocompleter should use for its template 
There are two events mixed in - onFocus (when the autocompleter takes focus) and onBlur (when the autocompleter loses focus)
See index.html for a working example.
License is MIT. See LICENSE file.
- Add a trigger to show the list without typing in the box (similar to clicking the down arrow on a select field)
 - Add in effects to make it smoother
 
