Creating a blog network…

Hi all,
I recently began using the WPMU latest edition. I’m trying to find a way to have 3 blogs on 3 different subdomains and on the main domain display posts from all 3 sub domains just as the posts are displayed on the front page of their respected subdomain.

All-in-all what I’m trying to do is, create a Blog Network for three different local sports teams, and have the main domain homepage, act as merging place for the 3 sub blogs to reside.

Is there a plugin for this or another solution?

Thanks,
Danny