Create a Phpbb extension that allows our users to have an anon button

I need an extension for phpbb that allows our users to post anonymously without having to log out and post as a guest. I would like a checkbox that will allow logged in members to make a post/topic anonymously. This must be able to work with topics, posts, quotes, and notifications. If you can make this extension happen, I will have more work for you as far as custom extensions.