captbrogers

An anti-spam captcha using jQuery’s UI slider. After the position of the slider is past 60% (default), it will enable the submit button. This will replace the input button specified as the submit button, if JavaScript is not enabled the button will show as expected.

WP Slider Captcha

An anti-spam captcha using jQuery's UI slider. After the position of the slider is past 60% (default), it will enable the submit button.

jameslafferty

This plugin allows you to display a form when users click on links inside of elements with a class you specify. The plugin uses a custom version of jQuery UI on the front end, and does not address situations where Javascript is turned off. It does provide a simple, attractive contact form inside of a modal dialog box.
If you find this plugin useful, please rate it and/or make a donation.
<h3>Internationalization (i18n)</h3>
This plugin has been translated into the languages listed below:
<ul>
<li>fr_FR – French. Thank you to Frederick Marcoux for contributing!</li>
</ul>
If you’re interested in doing a translation into your language, please let me know.

Contact Dialog

Enables display of an AJAX driven contact form when a user clicks on links with a specified class.

WP Slider Captcha vs Contact Dialog