Pingback, Trackback or alike new service.

Just don't want to forgot, it may remain open or postponed. I'm very interested in having more 'final' services as well as the current vertical services (node, user, taxonomy..), and this could be a great improvement for end-users to use (and test) services module, providing additional feedback. Current drupalers using services probably are very skilled, and this could be good, and bad.

http://drupal.org/project/trackback has base usage of 2k, http://drupal.org/project/pingback 600, these are the first two modules I've found, didn't dig further.