d3wp

This plugin generates nice jQuery powered sliding contact form in the left border of your WP blog. 
Contains client side validation and ajax powered mailing, so no page refresh is required. 
Admin section allows you to configure all form labels including error messages and form status messages.
<h3>Feedback</h3>
http://www.webdev3000.com/

WD3K Ajax Sliding Contact Form

An Ajax powered sliding contact form, based on Contactable (jQuery Plugin) By Philip Beel.

Bernhard Kau

WP Instant is deprecated and will be removed from the plugin directory on October 9, 2023, 12 years after its first release. You can find my other plugins <a href="https://profiles.wordpress.org/kau-boy/#content-plugins" rel="nofollow ugc">on my WordPress profile page</a>.
Integrates a Google Instant Search to your blog. The wp-instant plugin uses the Ajax.Updater function of script.aculo.us and the Form.Element.DelayedObserver class. A jQuery implementation will be following soon.
A list of all of my plugins can be found on the <a href="http://kau-boys.de/wordpress-plugins?lang=en" title="WordPress Plugins" rel="nofollow ugc">WordPress Plugin page</a> on my blog <a href="http://kau-boys.de" rel="nofollow ugc">kau-boys.de</a>.

WP Instant

Integrates a google instant search to your blog. The wp-instant pluing uses the Ajax.Updater function of script.aculo.us and the Form.Element.

WD3K Ajax Sliding Contact Form vs WP Instant