Paul Beakley I don’t know that a perfect all-in-one system exists if for no other reason than that not every platform communicates with every other platform, and folks are scattering now. But yeah, as Brad and Aaron mention, there’s commenting on posts, and pingbacks on post links. And yes, pingbacks work between all WordPress sites—used to get them all the time on the WordPress sites I hosted myself (one of which, geekstudies.org, I have since moved to WordPress.com just so I don’t have to worry about hackers anymore).