Connecting / interfacing with Facebook

Greetings,

Using the TwentyTen theme on Windows 7 64-bit
http://my-neighborhoods.net
http://www.facebook.com/robertmcclintock2011

I’ve heard that it is possible for someone to login to their Facebook account and then access my site to make comments with having to register at my site.

True? Not true?

I have enabled feeds into my Facebook account, and visitors can comment there and, if they click on the feed title and then click on “View original post” they are linked to my site, but not directly to comment.

Nearly All of the searches here lead me to “Topic Closed”

Any advice or solution?

Is there maybe a plug-in that works, is reliable and dependable?

I’m also investigating Twitter…

Thanks