Anonymous Posting plugin allows anonymous user to write their own posts using special page, no access to WP panel is needed.
It allows anonymous users/readers to write their own posts, writing is protected with reCAPTCHA. Plugin can be used for some kind of message board or public forum, you can configure comments under anonymous posts. Writing is avaialbe via special page/post.
To setup page for writing anonymous posts do the following:
Configuration options are explained on "Installation" page.
API key for reCAPTCHA is required to use reCAPTCHA.
If you know CSS please contact me, so I'll make 'new anonymous post' page look better:)