how to share posts from one domain into another

Excuse me if this is NOT the place to post this... I'm thinking this plugin will do this, but it's unclear to me.

What I'm looking to do is create a separate WP site, NOT NECESSARILY within my WPMU network, and then share the posts there in yet another WP site. I might want to share those posts with multiple other WP sites, but that's later...

The sites do not need to have single-sign-on or be synced.

How can I do this? OR, is it a better idea to do this within my WPMU network? And if so, how do I do it?