HackerNews OnePage Safari Extension:
http://blog.libinpan.com/SafariExtensions/HackerNews/HackerNews.safariextz
http://j.mp/hn4safari
So fat this extension just does one thing:
Provides users with the ability to browse Hacker News articles and comments without leaving the page.
It's a port from Tim Dupree's "Hacker News OnePage Chrome Extension". Thank you Tim!