Newsmixer is certainly worth taking a look at from a local news perspective.
Basically a news community site (based around Eastern Iowa, in the America) sets out to encourage and facilitate interaction and conversation on local news, integrating facebook into the mix, tapping into a strong online community without having to force potential members to sign up to another site.
It offers users the chance to comment directly, share short 'quip' comments (limited to 140 characters naturally) or to write a 'letter to the editor', showing all the freedom and open-ended opportunity the online world bring to news media.
Bringing the public and journalists closer - certainly not ground-breaking, but by making it the focus of the site rather than an optional element it does help to seed the sense of community?
And if it all works out, we'll all be doing it:
News Mixer is free and open source software, coded in Python with the Django Web development framework, and uses Facebook Connect for authentication. You can read more about our development process in our report, and find our source at Google Code.