Featured Blog Post Plugin (Like Ning?)

Hi all,
I was wondering if Multisite supports (or if there is a plug in that provides) a capability similar to Ning’s “Featured” post capability.

On Ning, every member has a “blog” of their own. They don’t have a full fledged site like multisite, but friends can read each other’s blog posts and you can read the public posts that others have released. But it’s all kinda buried deep in the site.

The Ning admins can see all the public posts and if there is one they think is noteworthy, they can “promote” it to appear on the front page of the site.

In WordPress terms, I’d like to be able to quickly scan all the public posts from the blogs in my multisite install and if there is a post that’s especially noteworthy, I’d like to “promote” it to the site’s main blog so that it becomes a post there as well. Whether the exact same post appears in both blogs or if a copy of it is made for the site’s main blog doesn’t really matter to me.

Anyone aware of a way to do this? I think it’s a powerful feature of Ning.