Ryan has a posting on a tool used within Microsoft PSS. SPSReport, which is very similar to PSS MPSReports for other products/technologies, collects a ton of information from the SharePoint Portal Server machine on which it is run;  that information includes:  event logs, metabase/IIS settings, hotfix lists, MD5 sums of relevant directories, important registry entries, etc., etc., etc.  The download contains a readme file that contains all of the various reports that it creates. This looks like a nifty tool that can be very helpful in a lot of situations.