Our detectives are back with the following intel on this WordPress site
The site is using the Dos project theme by Ivan Ruzevic (design & html/css) .
We could identify 3 plugins (there might be more) - Contact Form 7 , MailChimp List Subscribe Form and WP-Members Membership Plugin
Use the MailChimp List Subscribe plugin to quickly add a MailChimp signup form widget to your WordPress 2.8 or higher site.
The original membership plugin with content restriction, custom registration, and more.