Updated version of this post: Spice up your Drupal 6 site search field with a bit of jQuery and CSS
If you use Safari, or any other Webkit browser, the search field is even more enhanced. Here how it looks for you who don’t use a Webkit browser.
Aside from looking gorgeous, it adds value in terms of an enhanced user-experience. It works just like any other search field on Mac OS X. If you just want the nice Safari search field, take a look at http://drupal.org/project/safarisearch.
Here follows the code I use to implement this here on xdeb.org.