How to generate stats or reports for multi-sites? We've a large deployment of multi-sites, each site with its own database, and I am looking at generating reports from these sites and making those available online in some format. 

For e.g., our sites implement many redirects. I want to be able to pull a report on what redirects are in use by which site. I can readily do this via drush and shell scripts, but it would be nice to have a "stats site" to do the generating of these kinds of reports for all sites in a multi-site setup.
Here's how I do this:

I created a "meta" site and database in the system where I added a new table called "databases".  In that table I store the access info of all the DBs in the system.

Then loading an array from a query to that table, query the other DBs individually using the methods outlined here:
http://drupal.org/node/18429