Drupal's comment module gracefully handles anonymous posters when they want to leave messages. Administrators can choose whether those comments are left unattributed, whether anonymous commenters must leave personal information like a name and an email address, and so on. When it comes to full-fledged Node content, though, Drupal's a lot less flexible: the authors of anonymously written posts show up as "Anonymous," and you'd better like it. Fortunately, fixing that problem is the purpose of the Anonymous Posting module!
Setting up the module is painless; just visit its settings page, choose which content types should use its expanded Anonymous Posting options, and double-check to make sure anonymous users have permissions to create those content types. Once you've done that, a special set of options will appear on that content type's settings form. They're the same options that normally apply to comments, transplanted into the world of nodes.
Once you've set it up, usage is a no-brainer. Authenticated users will be able to create nodes just as they did before, but anonymous users preparing to author a post will see a Comment-module style list of personal information fields. Name, email, and home page are all supported. The result? Easy anonymous posting, complete with "Unverified" next to the author's name to prevent visitors from impersonating registered users of the site.
Anonymous Posting is available for Drupal 6 and 7. It's simple, streamlined, and because it still relies on Drupal's normal content authoring permissions it doesn't complicate the site permissions and security unnecessarily. Considering the potential for abuse of anonymous content creation, it's probably a good idea to combine this module with an anti-spam tool or a content moderation system.