HooThemes

Animated search form with Pure CSS3, replace search form with custom CSS styles.

Search Box

Animated search form with Pure CSS3, replace search form with custom CSS styles.

Arefly

Sometimes when user are using the search function of your blog. They may not know the full string of they want to search.
And this plugin will add a Search Keyword Hint (get hints from all tags) on the search form of your site.
So that user can find the things they want to search more easily.
Live Demo: <a href="http://www.arefly.com/" rel="nofollow ugc">Click Here</a> (Try enter any word in the search box.)
中文介紹請看<a href="http://www.arefly.com/wp-search-auto-match/" rel="nofollow ugc">這裏</a>

WP Search Auto Match

Add Search Keywork Hint like Google Search to your blog's search form.

Search Box vs WP Search Auto Match