Which import method?

Same blog moving from one place to another?
Moving_WordPress

Combining one into another (works good for those migrating from wordpress.com to their own hosted blog too): http://www.technosailor.com/wordpress-to-wordpress-import/

Syndicating posts from one to another? Pick a plugin from:
http://codex.wordpress.org/Plugins/Syndication

Hope one of those is right. 🙂