This isn't exactly news. There is a page that include several HN related services here : http://resourcey.com/site_details/2/news.ycombinator.com/
One of (IMHO) the problems with Hacker News is that there is no good way to store and locate meta information. So all the mashups, meetups, resources that have been inspired or built around and by the community live and die by being posted as stories. If someone isn't an obsessive reader of the site, it's pretty easy to miss these things. Resourcey is a good link, but you must also know it exists in order to find the other links.
Please, visit and upvote the resources you like, and add any resources you can think of. There are already a few gems there, for HN and other sites.