as consultant I am often facing to unknown SharePoint-installations. To have a fast overview to the Farm and the installed features etc. I use spsfarmreport from codeplex.
Easy to use, fully functional for 2007 AND 2010 SharePoint.
Also for documentation perhapses it is cool, because you have a file with a time stamp and also all settings to show the customer, what was the status after leaving the server.
The tool has to be run under propper permitted usercontext directly on one of the SharePointservers. After running the tool, a HTML-File will be generated. That file contains a lot informations about the farm and the settings.
Please find out this awsome tool. All informations can be loaded directly on CODEPLEX! Don’t forget to help the dev-guysolving problems, or even report them.