Consolidating Multiple Blogs into One Master Blog

Greetings all.

I’ve got multiple blogs on multiple product sites, and now i am starting a blog on our main company and my own personal site. What i would like to do is any time i post on one of the product blogs for it to automatically post on the “main” blog as well under the proper category and appear just like any other blog post (not just an RSS feed on the sidebar).
Basically, i want it to post in 2 places at once by only posting on 1 blog… i want it to have it’s own comments, etc…
But if i post on the “main” blog, i DON’T want it to flow down to the product blogs.

As there a plugin already created that will work for this?

TIA!