Renaming an open document is simple in Mountain Lion. You just have to find the hidden menu. Here’s where it is.
Command click the title of a page in the Title Bar of Safari to navigate quickly back to the Home Page of a website, or to other ‘group’ pages.
Command click the name of a document in the Title Bar (in some apps) to see exactly where the file is saved and open that folder in the Finder in a flash, revealing the file.
A document’s Title Bar shows the name you saved it with. Immediately to the left of that name is a small icon. That icon’s called a proxy icon. It has several uses.