this plugin is pretty neat and although it seems that is not managed by the author anymore it still works great.
I have found this thread http://wordpress.org/support/topic/plugin-mailchimp-widget-text-in-input-field?replies=3
regarding having a text in the input field e.g. "Email Address" and having it disappear when the user clicks there, but the offered answer is quite vague.
Any suggestions on this would be highly appreciated.
Thank you in advance!