Thread: Multisite setup with Main Categories Directory

Multisite setup with Main Categories Directory

This seemed simple enough when I started, but I haven't made any progress.
I have a WP 3.0 network with CP Ultimate installed on 3 sites. All 3 sites have their own niche categories and sub-categories.
Each site is a sub directory. domainname.com/autos/, domainname.com/pets/, etc.

What I am trying to do is create a landing page in the root directory that displays a dynamic list of all of the categories combining all 3 sites.
So for example if Site 1 is Automotive, Site 2 is Pets and Site 3 is Home & Garden. Then the main landing page would be a themed directory of all 3 sites showing ALL categories and linking to them.

I've looked at lots of plugins but I don't seem to find one that does this.
I thought about creating a separate index.php page for the root and just adding an sql query, then a repeating region for each, but I wanted to keep it within the WP and CP environment.

There just has to be a plugin that is used for this. What should I be searching for?

Has anyone done this?

Thanks in advance.