MavSuggest is an autocomplete (or text suggestion) mootools library which is able to query its results from a server-side script, or a local cache of JSON objects. The server-side script results can also be cached to allow for both a faster result, and less server traffic. There are many options to customize the text field and the search results to match the look and feel of your web-site or web application. Keyboard and mouse interactions make it as intuitive as using any other form field. Effects are optional for an even quicker response and display time.
THIS IS EARLY BETA! Just so you all know.

Link and Demo:
http://maveno.us/library/public/mavsuggest/EDIT: name changed from PredictiveText to MavSuggest... much easier to type, remember, and say. Plus it also accomplishes keeping all my scripts in my own namespace in a way. (mavsuggest, mavselectbox, etc.)
Censorship that comes from the outside assumes about people an inability to make reasoned choices -- George Carlin