I created a simple plugin called Easy WordPress Mailchimp Integration that simply adds a nice registration process to your Mailchimp mailing lists during WordPress user registration. Thats simple but so useful! You can customize the message that is displayed on the form registration, and well, that’s it! You can also view in users list users registered to one of your mailing list…. I hope you’ll like it!
- Arshad Cini - http://designbeep.com/2012/06/22/18-recently-released-free-wordpress-plugins-worth-checking-out/