Make comments "facebook comments" so my friends can comment?

When I write a new post, it allows people to comment via built-in comments-feature. I am hoping to change this to the facebook-comment “feature” that many sites have, but don’t know how 🙁
(I’m referring to how, if I’m logged into my facebook account, and I go to the local news’ website, it knows I’m logged-in to my facebook, and lets me comment via that ID. I want this setup on my site, so when I link a new post of mine to my facebook status, my friends can read my post and comment through their facebook ID’s/handles)

Thanks in advance for your help 😀