Quick contact box is a nice widget that shows phone numbers, address and email
Holler is a customisable contact form that uses AJAX to send messages without leaving the current page. It can be configured to send to a choice of a
SecureContact is a drop in form for users to contact you. It can be implemented on a page or a post. It offers enhaced security by using captcha image
WP-LightForm, the prettiest WordPress contact form.
A simple contactform for WordPress with antispam question
Easy Contact is a simple, highly extensible XHTML contact form featuring spam-reduction measures, GUI customization, and shortcode-based insertion.
A plugin to display .tel contact entries on your weblog.
UserVoice makes it easy to integrate the UserVoice customer feedback system into WordPress without having to directly edit template code.
Integrate IdeaScale crowdsourcing into WordPress without having to directly edit any template code.