This blog article shows how to script multi server queries through PowerShell that can be scheduled as a SQL Agent job. Unfortunately, outputing to the PowerShell window is not useful for something that is automated. I'd like to write the output to a table on my CMS. Enquired as to how that can be done in another thread.

http://blogs.msdn.com/b/sethus/archive/2009/04/09/execute-a-query-on-servers-in-central-management-server-group.aspx