Note: I created this module for a project in which I needed this, but probably I won't need it again so I hope there is someone who can take over maintenance. The code is pretty trivial though, it should keep working as long as the Drupal permissions API doesn't change.
Drupal is quite talkative in terms of showing off it's content. Often it makes content accessible which we actually don't want to show. That happens for instance very easily, if you're using nodes as content containers only - never really wanting to show the actual node page. Thanks to taxonomy node listings and other automatic node listings often these unstyled content containers land on the Google search index as soon as an Administrator has a look on this page and the page includes some SEO js, which then calls back to home about this URL path.
Module allows you enable bypass comment review. In this case any user that have permissions to post comment, will have ability skip approval.
That will be convenient in cases when you need improve communications for certain nodes.
You have an event and during this event anonymous users should be able to post comment without approval only on nodes, that related to this event.