Registration umbrella for add-ons?



I love the fact that, with one click installs, I can have blog software, a content management system, a forum and photo galleries on my site. I love the idea of creating a community site where other users can sign up and use these features. Does anyone know if there is a way to consolidate the registration process for each of these add-ons? For example, someone who signs up to write a blog using WordPress, must also sign up separately to post on my phbb forums. Is there a way to have only 1 registration that lets users do all? (either provided by DH, or by something else out there?)