Autocomplete textfields

In my search for a cool autocomplete script for my text fields, I came across one that I'd actually recommend.  If you aren't familiar with autocomplete scripts, just start typing a url into the latest version of firefox and you'll see what I mean.

Get the script: jQuery plguin: Autocomplete

The script uses jQuery, which is a javascript library.  It is really simple to use, everything is included in the download.  It comes with a demo page and you can use to make it work the way you want it.