Not sure if you are looking for something that works out of the box.. this is our homemade set up for what it's worth:
We have a few standard scripts on every server that can be accessed by all domains (using Apache Alias).
Ie the clicktracker, email gatherer, spam protected contact forms, search engine referrer logging.
The data that comes in from different servers and domains is stored on one central database server, and the data processing tools can stay universal for all projects and have to run only on the central database.
Very simple .. once it is in place
